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Journal of Foot and Ankle Research 2012, Volume 5 Suppl 1
http://www.jfootankleres.com/supplements/5/S1
JOURNAL OF FOOT
AND ANKLE RESEARCH
MEETING ABSTRACTS
Open Access
3rd Congress of the International Foot and Ankle
Biomechanics Community
Sydney, Australia. 11-13 April 2012
Edited by Joshua Burns and Fereshteh Pourkazemi
Published: 10 April 2012
These abstracts are available online at http://www.jfootankleres.com/supplements/5/S1
INTRODUCTION
I1
Biomechanics of footwear design
Richard Smith*, Caleb Wegener, Andy Greene, Angus Chard, Alycia Fong Yan
Exercise Health and Performance Research Group, The University of Sydney,
Sydney, NSW 2041, Australia
E-mail: [email protected]
Journal of Foot and Ankle Research 2012, 5(Suppl 1):I1
Background: The aim of the workshop is to explore the effects of
footwear design on lower limb motion and discuss research findings
relevant to the clinic and physical activity. Delegates will be actively
involved in a motion capture process where important lower limb joint
stress variables will be displayed in real time. The University of Sydney
researchers will raise footwear issues from a range of areas such as
children physical activity, adult walking and running, specific footwear
such as thongs (flip-flops), dance and experimental methodology.
During or on completion of this workshop, participants will be able to:
• Critically analyse footwear characteristics that are likely to influence
lower limb function during physical activity.
• Experience the use of state of the art technology to analyse lower limb
mechanics.
• Discuss the models and methods used to build knowledge about the
effect of footwear on lower limb mechanics.
• Recount clinical and research outcomes for the effect of footwear on
lower limb biomechanics during physical activity.
• Apply biomechanical principles to the effective choice of footwear for a
range of physical activities.
I2
Assessment of chronic ankle instability
Kathryn M Refshauge*, Claire E Hiller
Faculty of Health Sciences, University of Sydney, Sydney, NSW 2141, Australia
Chronic ankle instability is a complex problem which often follows ankle
sprain. This workshop will discuss the latest models of chronic ankle
instability and give an overview of the latest research in the area.
Assessment tools available in the clinic as well as the laboratory setting
will be demonstrated in the workshop with the opportunity for
participants to practice. Assessments covered will include; balance,
strength, joint laxity, motor control, and proprioception.
References
1. Arnold BL, De La Motte S, Linens S, et al: Ankle instability is associated
with balance impairments: a meta-analysis. Med Sci Sports Exerc 2009,
41:1048-1062.
2. Delahunt E, Coughlin G, Caulfield B, et al: Inclusion criteria when
investigating insufficiencies in chronic ankle instability. Med Sci Sports
Exerc 2010, 42:2106-2121.
3. Hertel J: Functional anatomy, pathomechanics, and pathophysiology of
lateral ankle instability. J Athl Train 2002, 37:364-375.
4. Hiller CE, Kilbreath SL, Refshauge KM: Chronic ankle instability: evolution
of the model. J Athl Train 2011, 46:133-141.
5. Hiller CE, Nightingale EJ, Lin CW, et al: Characteristics of People with
Recurrent Sprains: A systematic review with Meta-analysis. Br J Sports
Med 2011, 45:660-672.
6. Munn J, Sullivan SJ, Schneiders AG: Evidence of sensorimotor deficits in
functional ankle instability: a systematic review with meta-analysis. J Sci
Med Sport 2010, 13:2-12.
7. Wikstrom EA, Naik S, Lodha N, et al: Balance capabilities after lateral ankle
trauma and intervention: a meta-analysis. Med Sci Sports Exerc 2009,
41:1287-1295.
I3
Passive mechanical properties of human gastrocnemius muscle-tendon
units
Robert D Herbert*, Joanna Diong
The George Institute for Global Health, Sydney, NSW 2001, Australia
Background: The passive mechanical properties of skeletal muscle-tendon
units are important because they determine the amount of motion
available at joints. Human gastrocnemius muscle-tendon units are of
particular interest because this muscle is prone to develop contractures,
may have a role in lower limb overuse injuries, and is a common site of
muscle tears.
This workshop provides an introduction to what is known of the passive
properties of skeletal muscle-tendon units, focussing on human
gastrocnemius muscle-tendon units. The workshop will also provide an
introduction to the theory and practice of measuring passive mechanical
properties of human gastrocnemius muscle-tendon units in vivo.
Materials and methods: The mechanical properties of muscle-tendon
units have been investigated most frequently using in vitro preparations.
Testing of elastic properties most often utilises quasi-static protocols.
Dynamic protocols have also been used, particularly in studies that seek
also to determine viscous properties.
© 2012 various authors, licensee BioMed Central Ltd. All articles published in this supplement are distributed under the terms of the
Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Several methods have been developed for testing the mechanical
properties (usually elastic or pseudo-elastic properties) of human muscletendon units in vivo. Changes in length of human gastrocnemius muscletendon units may be estimated from changes in ankle and knee angles if
moment arms are known. Fascicle lengths can be measured with
ultrasound imaging or MRI. Recently methods have been developed for
measuring sarcomere lengths using invasive and minimally invasive
techniques. Achilles tendon force can be measured using invasive
methods such as fibre optic transducers. The length-tension properties of
the Achilles tendon can be estimated using non-invasive methods during
isometric contractions.
This workshop focuses on a method developed by our research team for
non-invasive measurement of the passive length-tension properties of
human gastrocnemius muscle-tendon units [1], as well as length-tension
properties of muscle fascicles and tendons [2]. The method involves
measuring ankle stiffness at a range of knee angles.
Conclusions: A range of methods is available for measuring the mechanical
properties of human gastrocnemius muscle-tendon units in vivo.
References
1. Hoang PD, Gorman RB, Todd G, Gandevia SC, Herbert RD: A new method
for measuring passive length-tension properties of human
gastrocnemius muscle in vivo. J Biomech 2005, 38:1333-1341.
2. Hoang PD, Herbert RD, Todd G, Gorman RB, Gandevia SC: Passive
mechanical properties of human gastrocnemius muscle-tendon unit,
muscle fascicles and tendon in vivo. J Exp Biol 2007, 210:4159-4168.
I4
Biomechanical assessment of the rheumatoid foot
Keith Rome1*, Gordon Hendry2
1
Health & Rehabilitation Research Institute, AUT University, Auckland, 0627,
New Zealand; 2University of Western Sydney, Sydney, Australia
Background: The aim of the workshop is to conduct a biomechanical
foot assessment of the rheumatoid foot. Participants will be involved in
an interactive workshop that includes patients with rheumatoid arthritis.
We will examine foot-related outcome tools designed to evaluate foot
function, pain and disability. Delegates will be divided into small groups
to analyse and interpret temporal and spatial gait parameters and plantar
pressure measurements.
Upon completion of this workshop, participants should be able to:
• Describe key components of a foot and ankle examination for the
rheumatology patient
• Discuss how current technology pertains to conceptualizing and treating
patients with rheumatic disease
• Describe the clinical and research applications of validated foot outcome
assessment instruments
• Formulate evidence-based non-pharmacological treatment strategies
based on pain mechanisms, unique clinical features and biomechanical
characteristics
• Demonstrate how biomechanical concepts and related treatment
strategies can be used to address complex cases of rheumatological
patients with foot pain, impairments and disability
KEYNOTE SPEAKER PRESENTATIONS
K1
Rearfoot and forefoot footfall patterns: implications for barefoot running
Joseph Hamill
University of Massachusetts, Amherst, MA, 01003, USA
Journal of Foot and Ankle Research 2012, 5(Suppl 1):K1
Approximately 75-80% of runners initiate contact with the running surface
on their heel and thus have a rearfoot or heel-toe footfall pattern. The
remaining 20-25% initially contact the ground with the foot flat with a
subsequent heel contact (midfoot pattern) or on their forefoot with no heel
contact (forefoot pattern). It is unclear why different footfall patterns exist or
why some runners naturally use different patterns. Some contemporary
training programs advocate the adoption of a mid- or forefoot footfall
pattern but there is little scientific evidence that a particular strike pattern is
Page 2 of 56
more efficient or less injury-prone than other patterns. In this presentation,
several studies that investigated differences among the footfall patterns
relative to oxygen consumption, impact characteristics, surface alterations
and lower extremity coordination will be presented. In addition, two
modeling studies will also be discussed. One study will determine, using
optimization techniques, the passive and active characteristics on the triceps
surae. The other study is a forward dynamics study with different cost
functions describing the different footfall patterns. Our basic premise in
these studies is that different footfall patterns serve different functional roles
in human running: a heel- or midfoot strike is used for endurance running,
and a forefoot strike is used for sprinting. We propose that one’s footfall
pattern is an intrinsic dynamic and thus difficult to alter. However, the
change from shod to barefoot running often requires an alteration in footfall
pattern that may ultimately lead to injury.
Acknowledgements: These studies could not have been accomplished
without the assistance of Ross Miller, Allison Gruber, Elizabeth Russell and
Julia Freedman.
K2
The legacy of Alex Stacoff for foot and footwear biomechanics research
Peter R Cavanagh
Department of Orthopaedics and Sports Medicine, University of Washington,
Seattle, WA 98195107, USA
Alex Stacoff was a Swiss biomechanics researcher and a key member of the
small group of scientists who founded the International Foot and Ankle
Biomechanics Community (i-FAB) in 2007. He was an active participant at
the first i-FAB Congress in September 2008, but he died tragically while
running, only three weeks later, at the young age of 58 years. The fact that
a flourishing i-FAB is now holding its 3rd Congress in Australia is part of
Alex’s legacy to the field. But there are other dimensions of his legacy on
both the personal and professional levels that I will explore, and hopefully
extend, in my presentation. Alex’s professional life was a model of
perseverance from which we all can learn. He earned his PhD some
20 years after changing course from an intended career as a schoolteacher.
Throughout this time he garnered a reputation for moderation, friendship,
mentorship, generosity, and collaborative work that is a model of how
research should be conducted. All this was achieved against a backdrop of
personal health challenges that would have caused many lesser individuals
to abandon professional activities altogether. Alex Stacoff’s professional
passion was to understand the biomechanics of the foot and shoe during
locomotion. He used both classical and novel methods, the later including
bone pin-mounted targets, magnetic resonance imaging kinematics, and
fluoroscopy. He expressed an early interest in learning from barefoot
running [1] and I will speculate on what he might of thought about the
current obsession with this topic. He also used accelerometers attached to
the body [2] and, following this lead, I will present new data from our
laboratory that demonstrates how skin-mounted accelerometers provide
reliable and insightful signals to understand bilateral and intra-subject
differences in the foot strike patterns of women distance runners.
References
1. Stacoff A, Nigg BM, Reinschmidt C, Van Den Bogert AJ, Lundberg A:
Tibiocalcaneal kinematics of barefoot versus shod running. J Biomech
2000, 33:1387-95.
2. Maffiuletti NA, Gorelick M, Kramers-de Quervain I, Bizzini M, Munzinger JP,
Tomasetti S, Stacoff A: Concurrent validity and intrasession reliability of
the IDEEA accelerometry system for the quantification of spatiotemporal
gait parameters. Gait Posture 2008, 27:160-163.
K3
Biomechanics of the ageing foot and ankle
Hylton B Menz
Musculoskeletal Research Centre, La Trobe University, Bundoora, Victoria
3086, Australia
Foot pain affects up to 24% of people aged over 65 years, and is
associated with difficulty undertaking activities of daily living, problems
with balance and gait, an increased risk of falls, and reduced healthrelated quality of life. Established risk factors for foot pain in this agegroup include female sex, obesity and chronic medical conditions such as
osteoarthritis and diabetes. However, given the significant age-related
changes in the structure and function of osseous, muscular and soft
tissues in the foot, the contribution of lower limb biomechanical factors
to the development of foot pain in older people is receiving increased
attention in the research literature. This presentation will provide an
overview of (i) the epidemiology of foot disorders in older people, (ii) the
physiological changes that occur in the ageing foot, (iii) the role of
biomechanics in understanding the potential mechanisms underlying the
development of foot pain, and (iv) the role of plantar pressure analysis
for the assessment and management of foot pain in this age-group.
K4
Abstract Withdrawn
Abstract Withdrawn:
K5
In vivo, intrinsic kinematics of the foot and ankle
Toni Arndt1,2*, Chris Nester3, Paul Lundgren1, Arne Lundberg1, Peter Wolf4
1
Karolinska Institute, Stockholm, 14186, Sweden; 2The Swedish School of
Sport and Health Sciences, Stockholm, 11486, Sweden; 3University of Salford,
Salford, M6 6PU, UK; 4ETH Zurich, 8092, Switzerland
Background: There are obvious problems involved in the accurate
description of movement of the intrinsic bones within the foot and ankle.
The 26 small bones are difficult, if not impossible to individually
represent with standard skin mounted markers for motion analysis [1,2].
This international research collaboration has performed a number of
studies in which invasively inserted intracortical pins are used for
anchoring reflective markers, thereby providing a direct representation of
the kinematics of the individual segments.
Materials and methods: A number of experimental sessions have been
performed at Karolinska Institute. The intracortical pins were inserted by
experienced orthopaedic surgeons under sterile conditions and using
local anaesthetics (Figure 1). Triads of reflective markers were attached to
the protruding ends of the pins and standard video based motion
analysis (Qualysis, Sweden) conducted. Data have been published
concerning walking [3] and slow running [4] and more recent work has
for the first time investigated applied scientific questions such as the
effect of shoe manipulations and in-shoe orthotics.
Results: Conclusions: A large range of fundamental data concerning foot
and ankle kinematics during walking and running and with various
manipulations have been collected and will be presented.
Page 3 of 56
Table 1(abstract K5) Mean total ranges of motion (ROM)
and standard deviations of motion about selected joints
in the sagittal, frontal and transverse planes during
walking. Data from six healthy, male subjects. From
Lundgren et al., 2008
plane
calc-tib
calc-tal
nav-tal
ROM
[°]
SD
cub-calc
cub-nav
ROM
[°]
ROM
[°]
ROM
[°]
SD
ROM
[°]
SD
SD
SD
sag
17.0
2.1
6.8
1.4
8.4
1.1
9.7
5.2
7.2
2.4
front
trans
11.3
7.3
3.5
2.4
9.8
7.5
1.8
2.0
14.9
16.3
6.1
6.5
11.3
8.1
3.9
2.0
8.8
8.9
4.4
4.3
References
1. Nester C, et al: Foot kinematics during walking measured using bone
and surface mounted markers. J Biomech 2007, 40:3412-3423.
2. Westblad P, et al: Differences in Ankle-Joint Complex Motion during the
Stance Phase of Walking as measured by Superficial or Bone anchored
Markers. Foot Ankle Int 2002, 23:856-863.
3. Lundgren P, et al: Invasive, in vivo measurement of rear, mid and
forefoot motion during walking. Gait Posture 2008, 28:93-100.
4. Arndt A, et al: Intrinsic foot kinematics measured in vivo during the
stance phase of slow running. J Biomech 2007, 40:2672-2678.
K6
An intelligent sport shoe to prevent ankle inversion sprain injury
Daniel TP Fong
Department of Orthopaedics and Traumatology, Faculty of Medicine, The
Chinese University of Hong Kong, Hong Kong
Background: Ankle sprain injury is common in sports. This study
presents an intelligent sport shoe to prevent it.
Materials and methods: (1) Sensing: Five subjects performed various
sporting motions with data collected from a plantar pressure system to
reconstruct the ankle supination torque determined from a motion capture
system with a force plate. Validation test on another five subjects was
conducted. (2) Identification: Six subjects performed simulated sub-injury
and non-injury trials with the dorsal foot kinematics measured by 8
wearable motion sensors. Data was used to train a support vector machine
to establish a mathematics algorithm for identification, which was validated
on another 6 subjects, with an expected accuracy of 90%. An uni-axial
gyrometer was placed at the position with the best accuracy for identifying
ankle sprain hazard, with a threshold suggested from a database of ankle
inversion velocity from real injury incidents, sub-injury trials and non-injury
motions. (3) Correction: Myoelectric stimulations with different delay time (0,
5, 10 and 15ms) were delivered to the peroneal muscles of 10 subjects
Figure 1(abstract K5) Computer tomography images of the marker locations on intracortical pins in foot and ankle segments.
performing unanticipated sub-injury trials in a laboratory. The effect was
quantified by the heel tilting angle and its velocity as determined by a
motion analysis system.
Results: (1) Sensing: a system with 3 pressure sensors was developed to
monitor the ankle supination torque with overall root mean square error
as 6.91Nm, which was 6% of the peak values recorded (Fong et al, 2008a).
(2) Identification: A method with one gyrometer at the heel to identify
hazardous motion with 91.3% accuracy was developed (Chu et al, 2010).
(3) Correction: significant reduction of the heel tilting angle and velocity
from 18 to 9-13 degrees and from 200-250 to 140-170 deg/s was achieved.
Conclusions: An intelligent anti-sprain sport shoe with a 3-step
intelligent system is successfully invented, and is soon being ready for
commercialization.
References
1. Fong DTP, Chan YY, Hong Y, Yung PSH, Fung KY, Chan KM: A threepressure-sensor (3PS) system for monitoring ankle supination torque
during sport motions. Journal of Biomechanics 2008, 41:2562-2566.
2. Chu VWS, Fong DTP, Chan YY, Yung PSH, Fung KY, Chan KM:
Differentiation of ankle sprain motion and common sporting motion by
ankle inversion velocity. Journal of Biomechanics 2010, 43:2035-2038.
ORAL PRESENTATIONS
Page 4 of 56
whether data was collected at the impact transient or the peak. Thirteen
articles did not report the footfall technique, while two studies reported
variable technique.
Conclusions: Evidence suggests the shock absorbing properties of
athletic footwear are effective during jump landings. Results varied
significantly in favour of the shod or barefoot condition depending on
whether data was collected at the impact transient or the peak. Footfall
technique appears to have a significant effect on vertical ground reaction
force. Activity-specific designs for footwear should take into account the
region of the shoe which absorbs the initial impact. Attention should be
given to develop consistent protocols for examining shock attenuation in
footwear research.
References
1. Lieberman DE, Venkadesan M, Werbel WA, Daoud AI, Dandrea S,
Davis IS, Mangeni RO, Pitsiladis Y: Foot strike patterns and collision
forces in habitually barefoot versus shod runners. Nature 2010,
463:531-535.
2. Jenkins DW, Cauthon DJ: Barefoot running claims and controversies. J Am
Podiatr Med Assoc 2011, 101:231-246.
3. Squadrone R, Gallozzi C: Biomechanical and physiological comparison of
barefoot and two shod conditions in experiences barefoot runners. J
Sports Med Phys Fitness 2009, 49:6-13.
O1
Shock attenuation in shoes compared to barefoot: a systematic review
Alycia Fong Yan1*, Claire Hiller2, Peter Sinclair1, Richard Smith1
1
Faculty of Health Science, The University of Sydney, Sydney, NSW, 2041,
Australia; 2Discipline of Physiotherapy, The University of Sydney, Sydney,
NSW, 2041, Australia
Journal of Foot and Ankle Research 2012, 5(Suppl 1):O1
O2
The effect of footwear on multi-segment foot kinematics during
running
Robin L Bauer*, Mukta N Joshi, Trevor R Klinkner, Stephen C Cobb
Department of Kinesiology, University of Wisconsin-Milwaukee, Milwaukee,
WI 53201, USA
Background: The debate over the advantages and disadvantages of
barefoot versus shod running has gained momentum recently [1,2] with
the retail market aiming to mimic the motion of the foot during barefoot
gait[3]. The aim of this study was to conduct a systematic review of articles
that compared shock attenuation in the shod condition to barefoot during
weight bearing activity in healthy individuals.
Materials and methods: >The major databases were searched for
the following keywords: barefoot, foot, feet, boot*, shoe*, impact, shock,
pressure, force, viscoelastic, and insert. Articles were screened
with inclusion and exclusion criteria set a priori. Articles were grouped
according to shoe type and where possible, a meta-analysis was used.
Results: Thirty-eight articles were found with 27 articles examining athletic
shoes compared to barefoot. For running, footwear attenuated loading rate
and tibial acceleration (Table 1). In contrast, the use of shoes increased
vertical ground reaction forces (vGRF) during running (Table 1) and
walking when measured at the impact transient. Results varied
significantly in favour of the shod or barefoot condition depending on
Background: Footwear is intended to prevent lower extremity injuries
caused by excessive foot-ground impacts and faulty mechanics. However,
no clear relationship between shoe habits and injury risk has been
established [1]. Many studies have examined barefoot versus shod
running kinematics, but the results have been equivocal [2,3]. A factor in
the inconsistent results could be the relationship between foot structure
and function. For example, Cobb et al. demonstrated significant walking
gait kinematic differences between participants with typical and low arch
foot structures using a multi-segment foot model [4]. The purpose of this
study was to investigate effects of footwear on multi-segment foot
kinematics during running in participants with low arch structure.
Materials and methods: Five healthy participants (26.8 ± 9.01 yrs; 171.5 ±
9.85 cm; 71.61 ± 15.46 kg) with low arch structure completed 10 running
trials at 4.0 (±10%) m/s in flat sandal and barefoot conditions. Marker
clusters placed on the skin or custom-built wands identified six functional
articulations: rearfoot complex (RC), calcaneonavicular complex (CNC),
calcaneocuboid joint (CC), medial forefoot (MFF), lateral forefoot (LFF), and
Table 1(abstract O1) Pooled effect of bare feet vs. athletic footwear during running (+’ve: attenuated in BF, –‘ve:
attenuated in shod)
Variable
Time of
Collection
# of Studies
n
Vertical Ground
Reaction Force
Impact
Transient
De Wit et al 2000, Divert et al 2005, Esnault 1985, Lieberman et al 2010
108 0.22 [0.20,
0.23]
<0.00001
Peak Force Alcantara et al 1996, Braunstein et al 2010, Dickinson et al 1986, Fong et al 2007,
Kerrigan et al 2009, Serrao & Amadio 2001, Squadrone & Gallozzi 2009,Stockton &
Dyson 1998
128 -0.03 [-0.07,
0.01]
0.19
Impact
Transient
72
-3.56 [-4.10,
-3.02]*
<0.00001
Peak Force Alcantara 1996, Serrao & Amadio 2001
11
-0.59 [-2.52,
1.35]*
0.55
Peak Force Alcantara et al 1996, McNair & Marshall 1994
18
-3.19 [-4.35,
-2.03]*
<0.00001
Loading Rate
Tibial
Acceleration
De Wit 2000, Lieberman 2010
*Standardised Mean Difference [95% CI].
Mean
Difference
[95% CI]
P Value
Page 5 of 56
Table 1(abstract O2) ROM mean ± SD results for Sagittal, Frontal and Transverse planes of motion
Barefoot
Flat
Sagittal Plane
Frontal Plane
Transverse Plane
Sagittal Plane
Frontal Plane
Transverse Plane
RC
22.16 ± 3.18
8.33 ± 1.72
16.99 ± 1.92
20.44 ± 5.30
8.10 ± 2.92
13.98 ± 2.95
CNC
10.85 ± 2.57
8.11 ± 2.67
6.35 ± 1.72
9.39 ± 4.02
6.14 ± 4.33
7.44 ± 2.35
CC
18.66 ± 1.86
9.69 ± 2.44
8.88 ± 2.92
14.48± 5.35
7.02 ± 2.75
7.45 ± 1.45
MFF
20.90 ± 4.68
20.14 ± 3.60
MTP
41.35 ± 5.39*
33.33 ± 1.76*
LFF
7.68 ± 3.19
9.34 ± 2.52
*indicates a significant difference (p < 0.05) between footwear conditions.
Table 2(abstract O2) Significant initial contact positions (p < 0.05) mean ± SD results between footwear conditions
Barefoot
Flat
Sagittal Plane
Frontal Plane
Transverse Plane
Sagittal Plane
Frontal Plane
Transverse Plane
CNC
2.81 ± 4.17
.38 ± 2.52
-1.53 ± 3.03*
1.51 ± 2.67
.07 ± 5.22
-4.34 ± 3.38*
CC
5.46 ± 7.60
-2.08 ± 2.84
-3.37 ± 3.23*
3.08 ± 4.03
2.60 ± 4.26
2.50 ± 1.97*
MTP
-14.12 ± 10.38*
-2.54 ± 7.63*
*indicates a significant difference (p < 0.05) between footwear conditions.
1st metatarsophalangeal complex (MTP). Repeated measures MANOVAs (a ≤
0.05) were used to analyze within-subject sagittal, frontal and transverse
plane range of motion (ROM) and initial contact position differences
between footwear conditions for the RC, CNC, and CC articulations.
Dependent t-tests (a ≤ 0.05) were performed to assess MTP, MFF and LFF
articulation sagittal plane ROM differences between the footwear conditions.
Results: ROM between conditions are shown in Table 1 and initial
contact positions are shown in Table 2.
Conclusions: Runners alter their gait from shod to barefoot running. The
ROM differences suggest runners adapt by increasing motion during
stance phase. Initial contact positions demonstrate differences in strike
pattern. Higher sagittal plane values for barefoot trials may indicate more
midfoot/forefoot landing. These data may enhance the understanding of
shoe-wear and running-related injuries.
Acknowledgements: This study was supported by a grant from the UWMilwaukee Graduate School.
References
1. Wen D: Risk factors for overuse injuries in runners. Curr Sports Med Rep
2007, 6:307-313.
2. De Wit B, Clercq D, Aerts P: Biomechanical analysis of the stance phase
during barefoot and shod running. J Biomech 2000, 33:269-278.
3. Lieberman D, Venkadesan M, Werbel W, Daoud A, Andrea S, Davis I,
Mang’Eni R, Pitsiladis Y: Foot strike patterns and collision forces in
habitually barefoot versus shod runners. Nature 2010, 463:531-535.
4. Cobb S, Tis L, Johnson J, Wang Y, Geil M, McCarty F: The effect of lowmobile foot posture on multi-segment medial foot model gait
kinematics. Gait Posture 2009, 30:334-339.
information on the mechanical properties of the shoes. A justified
selection protocol of sports and leisure shoes based on static and
dynamic shoe properties considering the intended use is essential. Today,
commonly accepted dynamic test protocols for (sports) shoes do not
exist.
The development of an artificial parametric foot as part of an innovative
robot gait simulator is a tool to objectify shoe properties independently
from possible compensations encountered during assessment of test
persons. This contribution discusses the development of an artificial foot
enabling objective testing of the mechanical and functional properties of
sports and leisure shoes.
Materials and methods: An artificial foot consisting of the shank, the
rear foot, the mid foot and the toes was designed based on a
measurement protocol for barefoot running using 12 active markers
sampled at 400 Hz [1]. The foot was manufactured using additive layered
fabrication (Figure 1).
Results: Based on measurements the design of this initial foot was
optimized with respect to functionality and appropriate shoe fit. The
multi segment design of this foot is shown in figure 2. Optimisation was
realized by changing 3 different regions: (a) orientation of the subtalar
O3
Development of an artificial foot enabling the simulation of the natural
behaviour of the human unroll of the foot during walking and running
Helga Vertommen1*, Eveline De Raeve1, Wim Dewindt1, Carel Van den Bosch2,
Fred Holtkamp4, Louis Peeraer1,3,4
1
MOBILAB, University College Kempen, Geel, Belgium; 2Greentech
Engineering, Eindhoven, The Netherlands; 3Faculty of Kinesiology and
Rehabilitation Sciences, KULeuven, Leuven, Belgium; 4Fontys University of
Applied Sciences, Eindhoven, The Netherlands
Background: The percentage of sports and leisure shoes sold worldwide
is gradually increasing. However, consumers have little or no objective
Figure 1(abstract O3) Initial design of the artificial foot.
Figure 2(abstract O3) Second design of artificial foot.
joint axis, (b) segmentation of the mid foot into 6 different slices
matching realistic functional behaviour during roll off (c) segmentation of
the toe section into two parts (big toe and lesser toes) to simulate a
better forefoot roll off. Foot segments are connected with springs and
dampers, each of them designed on literature findings and model
simulations.
Conclusions: An improved artificial foot design with built-in springs and
dampers for objective testing of shoe properties is realized. The design
needs further elaboration with respect to geometry, foot axes and
functional behaviour. This mechanical foot is a promising tool to help us
understand mechanical properties of shoes using strictly standardised
testing protocols using mechanical gait simulators.
Reference
1. Vertommen H, De Raeve E, Peeraer L: i-FAB Seattle. Abstract 2010.
O4
Effect of rollover footwear on metabolic cost of ambulation, lower limb
kinematics, kinetics, and EMG related muscle activity during walking
Saeed Forghany1,2, Christopher Nester1*, Barry Richards1, Anna Hatton1
1
School of Health Sciences, University of Salford, UK; 2Musculoskeletal
Research Centre, School of Rehabilitation Sciences, Isfahan University of
Medical Sciences, Iran
Background: Footwear with a curved sole profile shifts the point of
contact between the shoe and floor anteriorly compared to a flat shoe.
There have been various reports of changes in ground reaction forces,
external joint moments, and (rather inconclusively) muscle activity and
energy consumption during walking in this “rollover” footwear [1-6]. The
aim of this study was to investigate the effect of two types of rollover
footwear (one a new prototype) on walking speed, metabolic cost of gait,
lower limb kinematics, kinetics and EMG muscle activity.
Methods: Twenty subjects walked in four footwear conditions: (1) a flat
control shoe; (2) a flat control shoe weighted to match the mass of the
new rollover shoe prototype; (3) the new prototype rollover shoe; (4) a
MBT shoe. Data relating to metabolic energy and temporal aspects of
gait were collected during a 6 minute walk test. Data on the lower limb
kinematics, joint moments, muscle activity and foot pressure were
collected during walking on a straight 10 metre course.
Results: The curved sole moved the contact point under the shoe
anteriorly during early stance. This altered ankle moments and reduced
ankle plantarflexion after initial contact. In mid stance the roll over
footwear reduced ankle dorsiflexion and overall the ankle moved less in
roll over footwear. Ground reaction force loading rates were increased by
the rollover footwear. There were notable elevations in early stance calf
Page 6 of 56
EMG activity. Effects on energy cost of ambulation were negligible.
Rollover footwear reduced plantar pressures under the heel and forefoot,
and redistributed pressure towards the midfoot. Shoe weight had no
effect on any parameters.
Conclusion: Rollover footwear is able to modify ankle kinematics and
moments and the activity of some ankle musculature. Effects proximal to
the leg were small. There were no effects on the temporal or energy
aspects of gait.
Acknowledgement: This work was funded by SSL International Ltd.
References
1. Nigg, et al: Effect of an unstable shoe construction on lower extremity
gait characteristics. Clin Biomech 2006, 21:82-88.
2. Romkes, et al: Changes in gait and EMG when walking with the Masai
Barefoot Technique. Clin Biomech 2006, 21:75-81.
3. Myers, et al: Biomechanical implications of the negative heel rocker sole
shoe: gait kinematics and kinetics. Gait Posture 2006, 24:323-330.
4. Buchecker, et al: Lower extremity joint loading during level walking with
Masai barefoot technology shoes in overweight males. Scand J Med Sci
Sports 2010.
5. Van Engelen, et al: Metabolic cost and mechanical work during walking
after tibiotalar arthrodesis and the influence of footwear. Clin Biomech
2010, 25:809-815.
6. Hansen, et al: Effect of rocker shoe radius on oxygen consumption rate
in young able-bodied persons. J Biomech 2011, 44:1021-1024.
O5
The relationship between sole curvature of roll over footwear and
changes in gait
Saeed Forghany1,2, Christopher Nester1*, Barry Richards1
1
School of Health Sciences, University of Salford, UK; 2Musculoskeletal
Research Centre, School of Rehabilitation Sciences, Isfahan University of
Medical Sciences, Iran
Background: Footwear with a curved sole profile remains popular and
there is evidence of its effects on gait and posture [1,2]. Existing literature
describes how different styles of roll over footwear affect gait, although
the effects of the precise radii of the curve of the sole on the gait rocker
function and other reported effects have not been investigated. The aim
of this study was to relate the radii of the soles of two roll over footwear
products to their effects on walking.
Materials and methods: Lower limb kinematic and GRF data was
collected from twenty subjects during walking in four footwear conditions:
flat control shoe, weighted flat control shoe, the new prototype rollover
shoe and a MBT shoe. The static sole radii of all footwear was calculated
for all and distinct parts of the sole, and correlated with radii of the gait
rollover shapes as described by Hansen et al [3,4].
Results: The radii of the foot–shoe roll-over shapes were significantly
changed in response to different shoe conditions (p<0.001), but leg and
thigh radii were not. The MBT shoes demonstrated a low positive
correlation between the radius of foot-shoe roll-over shape and the static
sole radii (whole sole) (r = 0.32; p = 0.04) and the radii of the heel area of
the sole (r = 0.39; p = 0.01). The new prototype shoes showed no
statistically significant correlations.
Conclusion: The results of this study indicate that the static curve of the
sole is not the main factor influencing gait. It appears that the extent to
which the curved sole deforms dynamically during gait (i.e. shoe bending
stiffness) influences the strength of the relationship between sole
curvature and changes in gait.
References
1. Nigg , et al: Effect of an unstable shoe construction on lower extremity
gait characteristics. Clin Biomech 2006, 21:82-8.
2. Romkes , et al: Changes in gait and EMG when walking with the Masai
Barefoot Technique. Clin Biomech 2006, 21:75-81.
3. Hansen , et al: Effects of shoe heel height on biologic rollover
characteristics during walking. J Rehabil Res Dev 2004, 41:547-554.
4. Hansen , et al: Effective rocker shapes used by able-bodied persons for
walking and fore-aft swaying: Implications for design of ankle–foot
prostheses. Gait Posture 2010, 32:181-184.
O6
What is the best Rocker Shoe design?
Jonathan Chapman1*, Stephen Preece1, Christopher Nester1,
Bjoern Braunstein2, Angela Höhne2, Gert-Peter Brüggermann2
1
School of Health, Sport and Rehabilitation Sciences, University of Salford,
UK; 2Institute of Biomechanics and Orthopaedics, German Sport University,
Cologne, Germany
Background: Rocker shoes are often prescribed to reduce in-shoe
pressures in order to minimise the risk of ulceration in diabetic patients.
However, the efficacy of the 3 principal design features of a rocker shoe
(apex position, rocker angle and apex angle, see Figure 1) is unknown.
Only one known study to date has systematically varied 2 of the 3 design
features [1]. Therefore the aim of this study was to investigate the effect
of the three principal design features, quantify inter subject variability
and establish whether there is any difference in the response of the
diabetic and the healthy cohort by recording in shoe plantar pressure.
Materials and methods: By using 12 different rocker shoe designs and a
control shoe, we systematically varied each design feature apex position
(50-70% of shoe length), rocker angle (10-30°) and apex angle (70-100° to
longitudinal shoe axis). For each shoe, peak 1st metatarsophalangeal joint
(MPJ) pressure was measured during walking. Data was collected from 30
diabetic and 30 healthy subjects and repeated measures ANOVA used to
investigate the mean effect of each feature. Descriptive statistics were
used to investigate inter-subject variability and a two-way ANOVA was
used to compare the response between the diabetic and healthy cohort.
Results: All three design features had a significant effect on peak 1st MPJ
pressure. However, there was considerable inter-subject variability in the
optimal rocker angle and optimal apex position. In contrast, an apex angle
of between 90-100° resulted in minimal pressures across almost all subjects.
Conclusion: The results suggest that pressure offloading can be achieved
by employing an apex angle of approximately 95°. However, rocker angle
and apex position should be chosen on individual by individual basis.
Acknowledgments: The research leading to these results has received
funding from the European Community’s Seventh Framework Programme
Page 7 of 56
([FP7/2007-2013] [FP7/2007-2011]) under grant agreement n° [NMP2-SE2009-229261].
Reference
1. Van Schie C, et al: Design criteria for rigid rocker shoes. Foot Ankle Int
2000, 21:833-844.
O7
Effects of unstable footwear on joint reactions and muscle forces: an
inverse dynamics study
Michael Schwarze1*, Frank Seehaus1, Christof Hurschler1, Hazibullah Waizy2
1
Laboratory for Biomechanics and Biomaterials, Hannover Medical School,
30625 Hannover, Germany; 2Department of Orthopaedics, Hannover Medical
School, 30625 Hannover, Germany
Background: Unstable shoe designs should support the muscle activity
and promise the treatment of leg, back and foot problems. According to
manufacturers, they should activate additional muscles and reduce joint
reaction forces. Goal of this study is to investigate the effect of an
unstable shoe design to gait patterns of healthy volunteers and by the
means of inverse dynamic multi-body simulation.
Materials and methods: Seven subjects (age: 46.5±7.6 years, weight:
91.7±11.1kg) familiar with unstable shoes performed five trials of level
walking in three testing conditions (barefoot, conventional and unstable
shoe). As an unstable shoe the Anti-Step (Chung-Shi) was chosen.
Kinematic and kinetic data was acquired with a motion capturing system
(Vicon) and two forceplates (AMTI). The inverse dynamics model of the
lower extremity consists of nine rigid bodies which are connected with
idealized joints and a set of all relevant muscles.
Results: Comparing walking speed while walking barefoot or with stable
and unstable shoe designs, the volunteers walked significantly slower in the
barefoot case (p<.003). Preliminary multi body-simulation data was analysed
for four out of seven volunteers. Peak joint reaction forces were reduced by
29% when comparing conventional with unstable shoes (Figure 2). Muscle
activation changes in magnitude for all groups (Figure 1). The timing
Figure 1(abstract O6) Apex position, rocker angle and apex angle in a rocker shoe.
Page 8 of 56
Figure 1(abstract O7) Muscle activation of the ankle muscle groups around the ankle for one subject. Lines representing results for barefoot (red),
conventional shoe design (green) and unstable shoe design (blue).
remains similar, except the everter group activating only with the unstable
shoe during stance phase.
Conclusions: The simulation reveals muscle activation patterns that
indicate instability along the inversion/eversion axis of the ankle, which is
also found in the literature [1]. The additional activation of the everter
group during stance phase possibly exercises this group and could lead
to an effect on the arch of the foot.
Reference
1. Nigg B, Hintzen S, Ferber R: Effect of an unstable shoe construction on
lower extremity gait characteristics. Clin Biomech 2006, 21:82-88.
O8
Effects of extrinsic rearfoot posting in custom foot orthoses on frontal
plane kinematics and kinetics
Scott Telfer*, Mandy Abbot, Daniel Rafferty, Jim Woodburn
School of Health and Life Sciences, Glasgow Caledonian University,
Glasgow, UK
Background: A regularly prescribed design variable in foot orthoses (FOs)
is the addition of an extrinsic rearfoot post, a feature which can be angled
medially or laterally and is intended to control movement of the calcaneus
during the stance phase of gait [1]. This study aims to investigate whether
introducing incremental changes in this feature will produce a linear trend
in the user’s frontal plane biomechanical responses, and whether
responses vary between normal and pronated feet.
Materials and methods: Ten participants were recruited: five healthy
controls and five patients with a symptomatic pronated foot type.
Computer aided design (CAD) models of a pair of customised FOs were
produced from a 3D surface scan of the subject’s feet using orthotic
design software. These devices were manufactured and checked for
comfort and fit. The original CAD design was subsequently altered to
produce nine additional FO designs (for one randomly chosen foot) with
posting levels varying in 2° steps from 6° lateral to 10° medial and these
were then manufactured. After wearing the original FOs for one week,
participants came to the gait laboratory for assessment and kinematic
and kinetic measurements of the lower limbs were made during gait for
each orthotic condition.
Results: Linear trends for the reduction of peak rearfoot eversion were
measured (control group R 2 =0.9, P=0.003; patient group R 2 =0.86,
P=0.04) across the tested orthotic conditions (Figure 1). Differences in
the effects of the devices on peak rearfoot eversion in the control and
patient group were found to be significant (P<0.001). Changes in ankle
and knee adduction moments were not significant for trends or
between groups.
Conclusions: These results provide preliminary quantitative mode of
action evidence for the prescription of personalised FOs intended to
control rearfoot eversion through the use of an extrinsic rearfoot post.
Care should be taken when extrapolating results from FO research carried
out on normal foot types to clinical populations.
Reference
1. Hunter S, Dolan MG, Davis JM: Introduction to orthotic therapy. Foot
orthotics in therapy and sport Champaign: Human Kinetics: Frey F 1995,
1-9.
Page 9 of 56
O9
The effect of different depths of medial heel skive on plantar pressures
Daniel R Bonanno1,2*, Cheryl Y Zhang1, Rose C Farrugia1, Matthew G Bull1,
Anita Raspovic1,2, Adam R Bird1,2, Karl B Landorf1,2
1
Department of Podiatry, Faculty of Health Sciences, La Trobe University,
Bundoora, Victoria, 3086, Australia; 2Musculoskeletal Research Centre, Faculty
of Health Sciences, La Trobe University, Bundoora, Victoria, 3086, Australia
Background: Foot orthoses are often used to treat lower limb injuries
associated with excessive pronation. There are many orthotic modifications
available for this purpose, with one being the medial heel skive. However,
empirical evidence for the mechanical effects of the medial heel skive is
limited. This study aimed to evaluate the effect that different depths of
medial heel skive have on plantar pressures.
Materials and methods: Thirty healthy adults aged over 18 years with flat
feet and no current foot pain or deformity participated in this study. Using
the in-shoe Pedar-X® system, plantar pressure data were collected for the
heel, midfoot and forefoot while participants walked along an 8 metre
walkway wearing a standardised shoe. Experimental conditions included the
following 4 customised orthotic variants: (i) no heel skive, (ii) 2 mm heel
skive, (iii) 4 mm heel skive and (iv) 6 mm heel skive.
Results: Compared to the foot orthoses with no heel skive, statistically
significant increases in peak pressure were observed at the medial heel –
there was a 15% increase (p = 0.001) with the 4 mm skive and a 29%
increase (p < 0.001) with the 6 mm skive. No significant change was
observed with the 2 mm heel skive. With respect to the midfoot and
forefoot, there were no significant differences between the orthoses.
Conclusions: The results of this study indicate that a medial heel skive of 4
or 6 mm can increase peak pressure under the medial heel in asymptomatic
flat-footed individuals. Plantar pressures at the midfoot and forefoot were
not affected by a medial heel skive of 2, 4 or 6 mm. These findings provide
some evidence for the effects of the medial heel skive orthotic modification.
Figure 2(abstract O7) Joint reaction forces in the ankle for one subject.
Lines representing results for barefoot (red), conventional shoe design
(green) and unstable shoe design (blue).
O10
Motion of the rearfoot, ankle and subtalar joints and ankle moments when
wearing lateral wedge insoles – results from bone anchored markers
Richard Jones1*, Chris Nester1, Anmin Liu1, Peter Wolf2, Anton Arndt3,
Paul Lundgren3, Arne Lundberg3
1
Centre for Health Sciences Research, University of Salford, Salford, Greater
Manchester, M6 6PU, UK; 2Sensory Motor Laboratory, ETH Zurich Switzerland;
3
Karolinska Hospital , Huddinge, Sweden
Figure 1(abstract O8) Reduction in peak rearfoot eversion for control and patient groups across all orthotic conditions. 6L: 6° lateral post; 0N: neutral
posting; 10M: 10° medial post. Error bars are ±1SD.
Page 10 of 56
Table 1(abstract O10) Raw changes in three segments
(-ve change degs = increased eversion) and ankle
moment (negative change = increased eversion moment
nm/kg) in the 5 individuals compared to control
condition
S1
S2
S3
S4
S5
Tibia-talus y
-2.91
-1.18
-1.71
-1.14
-3.81
Talo-calcaneal y
Tibia-calcaneal
-4.27
-1.19
-1.96
-2.15
-6.04
-4.54
-2.34
-1.90
-2.94
-1.19
Ankle joint coronal moment
-0.09
-0.02
XX
-0.05
-0.06
Background: Knee osteoarthritis is a debilitating condition and increased
dynamic loading at the knee has been linked with increased progression
of the disease. Lateral wedge insoles have been used in clinical practice
since the late 1980s. It is theorised that lateral wedge insoles increase the
subtalar joint valgus orientation and increase the ankle valgus moment [1],
with subsequent reduced knee varus moments [2]. Results have shown
that both clinical success and reductions in knee loading vary between
people. Differences could be due to person specific foot biomechanics.
The aim of this study was to determine the changes in frontal plane foot
and ankle motion and moment due to a lateral wedge orthosis.
Materials and methods: Five healthy individuals participated in the study
(age, height). An intracortical pin approach to measurement of foot motion
was adopted because it enables effects of the orthosis at the individual
ankle and subtalar joints to be identified. Accordingly, 1.2 mm intracortical
pins were inserted into 9 bones of the foot and leg under local anaesthesia
and reflective markers attached to the pins. Individuals walked over a force
platform ten times in a control shoe condition and the Salford Lateral
Wedge Technology insole™. All data were normalised to stance phase.
Orthotic effect was evaluated using motions between tibia-talus, taluscalcaneus, and tibia-calcaneus during the first 50% of stance phase.
Results: Conclusions: Although the lateral wedge insole offers a change in
the ankle valgus moment, each person’s kinematic response varied (Table 1).
This demonstrates that the motions do not occur at one segment as per
previous research [1] and therefore other motions in adjacent joints needs
to be considered. This is potentially one of the reasons why some people do
not respond to the orthosis and suggests that use of biomechanical foot
classifications could enable more targeted use of lateral wedge insoles [3].
References
1. Kakihana W, Akai M, Nakazawa K, Takashima T, Naito K, Torii S: Effects of
laterally wedged insoles on knee and subtalar joint moments. Arch Phy
Med Rehabil 2005, 86(7):1465-1471.
2. Jones RK, Chapman GJ, Findlow AH, Parkes M, Forsythe L, Felson DT: Does
increased loading occur on the contralateral side in medial knee
osteoarthritis and what impact do lateral wedges have on this?
Osteoarthritis Cartilage 2011, Suppl 1: S176.
3. Chapman GJ, Jones RK, Findlow AH, Parkes M, Forsythe L, Felson DT: Can
we predict responders to lateral wedge insoles in patients with medial
knee osteoarthritis. Osteoarthritis Cartilage 2011, Suppl 1: S934.
O11
The effectiveness of using in-shoe plantar pressure assessment and
monitoring in prescription therapeutic footwear to prevent plantar foot
ulcer recurrence in diabetic patients: a multicenter randomized
controlled trial
Sicco A Bus1*, Mark LJ Arts1, Roelof Waaijman1, Mirjam de Haart1,
Tessa Busch-Westbroek1, Sjef G van Baal2, Frans Nollet1
1
Department of Rehabilitation, Academic Medical Centre, University of
Amsterdam, Amsterdam, the Netherlands; 2Department of Surgery,
Ziekenhuisgroep Twente, location Almelo, Almelo, the Netherlands
Background: Diabetic patients at high risk for foot ulceration are often
prescribed with custom-made therapeutic footwear. However, the
evidence base to support the use of this footwear for ulcer prevention is
still meagre [1]. The lack of offloading efficacy may play a role in this. Inshoe plantar pressure assessment is a valuable tool for evaluating
footwear and guiding modifications to optimize the footwear’s offloading
properties [2]. The aim of this multicenter randomized trial was to assess
the effectiveness of this approach and long-term pressure monitoring in
prescription footwear to prevent plantar foot ulcer recurrence in
neuropathic diabetic patients.
Materials and methods: A total 171 neuropathic diabetic patients with a
recently healed plantar foot ulcer were randomized to an intervention group
that had custom-made footwear which was evaluated, optimized and
monitored at 3-monthly visits using in-shoe plantar pressure analysis or a
control group that had custom-made footwear which was evaluated
according to current practice. Barefoot peak pressures, adherence to
footwear use, and number of daily footsteps were also assessed in each
patient. The primary outcome was percentage plantar foot ulcers in
18 months follow-up, which was hypothesized to be 50% lower in the
intervention group than control group.
Results: Baseline patient characteristics were not significantly different
between study groups. Due to the footwear optimization approach, in-shoe
peak pressures at the previous ulcer and other high pressure locations were
significantly lower with ~20% in the intervention group than control group
during 18 months follow-up. This is a “work-in-progress” abstract. Final data
on clinical outcome will be collected early 2012 and will therefore be
presented for the first time at i-FAB2012.
Conclusion: The results of this study will provide a comprehensive view
on the role of pressure offloading and other important biomechanical and
behavioural factors in the prevention of foot ulceration in high-risk
diabetic patients.
Acknowledgements: This abstract is presented on behalf of the DIAbetic
Foot Orthopaedic Shoe (DIAFOS) trial study group, involving 10 diabetic
foot centres and 9 orthopaedic footwear companies in the Netherlands.
References
1. Bus SA, Valk GD, van Deursen RW, Armstrong DG, Caravaggi C, Hlavácek P,
Bakker K, Cavanagh PR: The effectiveness of footwear and offloading
interventions to prevent and heal foot ulcers and reduce plantar pressure
in diabetes: a systematic review. Diabetes Metab Res Rev 2008, 24:S162-180.
2. Bus SA, Haspels R, Busch-Westbroek TE: Evaluation and optimization of
therapeutic footwear for neuropathic diabetic foot patients using inshoe plantar pressure analysis. Diabetes Care 2011, 34:1595-1600.
O12
Mapping load transfer from the plantar surface of the foot to the walls
of the total contact cast (TCC)
Lindy Begg1*, Patrick McLaughlin2,3, Leon Manning1, Axel Kalpen4,
Mauro Vicaretti1, John Fletcher1, Joshua Burns1,5
1
Foot Wound Clinic, Department of Surgery, Westmead Hospital, 2145,
Australia; 2School of Biomedical and Health Sciences, Faculty of Health,
Engineering and Science, Victoria University, Melbourne 8001, Australia;
3
Institute of Sport, Exercise and Active Living, Victoria University, Melbourne,
8001, Australia; 4Novel Biomechanics Lab, Munich, Germany; 5Institute for
Neuroscience and Muscle Research, The Children’s Hospital at Westmead/
Paediatric Gait Analysis Service of New South Wales/Faculty of Health
Sciences, The University of Sydney, NSW, 2145, Australia
Background: The mechanism of offloading plantar pressure with a TCC is
by redistributing weight-bearing load across the entire plantar surface of
the foot and increasing the plantar surface contact area [1]. An additional
mechanism is by transfer of load to the cast walls however these studies
relied on indirect methods [2-4]. No previous research has directly
measured the load on the cast wall.
The aim of this pilot study was to:
1. Systematically map pressure between the walls of the TCC and the
lower limb to identify those areas of greatest pressure.
2. To directly measure load transfer from the plantar surface of the foot
to the cast walls.
Materials and methods: A TCC was applied to a 20 year old healthy
female and a 32 year old female with a 17 year history of Diabetes Mellitus
without complications. The TCC was bi-valved and a capacitance sensor
insole (pedar®, novel Gmbh, Germany) was placed on to the plantar area of
the TCC and another into the participant’s sport shoe. Pliance® sensors
were also placed along the lower leg (pliance®, novel Gmbh, Germany).
Both sensors collected data simultaneously. After completion of all seven
trials measuring each location of the cast wall, the cast wall of the TCC was
cut down to create a shoe-cast.
Results: The two highest pressure locations from the cast-wall pliance®
sensors were: posterior to the lateral malleolus and the extensor
retinaculum. The average force per step for the resultant cast wall load was
159.2N for the participant with diabetes and 104.8N for the participant
without diabetes. With the use of direct measurement it was established
that there was a load transfer of 34% from the plantar surface of the foot to
the cast walls of a TCC worn by a participant with Diabetes and for the
healthy participant 23%.
Conclusions: The results supported the estimated values of 30-35% of
load transfer by previous researchers who calculated cast wall data from
indirect (plantar) measures.
Acknowledgement: This study was funded by the Australian Podiatry
Education and Research Foundation.
References
1. Hartsell HD, Fellner C, Frantz R, Saltzman CL: Prosthetics and orthotics
science: the repeatability of total contact cast applications: implications
for clinical trials. J Prosthet Orthot 2001, 13:4-9.
2. Leibner ED, Brodsky JW, Pollo FE, Baum BS, Edmonds BW: Unloading
mechanism in the total contact cast. FootAnkle Int 2006, 27:281-285.
3. Shaw JE, Hsi WL, Ulbrecht JS, Norkitis A, Becker MB, Cavanagh PR: The
mechanism of plantar unloading in total contact casts: implications for
design and clinical use. Foot Ankle Int 1997, 18:809-817.
4. Tanaka H, Nagata K, Goto T, Hoshiko H, Inoue A: The effect of the patella
tendon-bearing cast on loading. J bone joint surg 2000, 82-B:228-232.
O13
Foot type biomechanics in diabetic and not diabetic subjects
Zimi Sawacha1*, Annamaria Guiotto1, Gabriella Guarneri2, Angelo aogaro2,
Claudio Cobelli1
1
Department of Information Engineering, University of Padova, Padova,
35100, Italy; 2Department of Clinical Medicine and Metabolic Disease,
University Polyclinic, Padova, 35136, Italy
Background: The aim of this study was to investigate the role of foot
morphology with respect to diabetes and peripheral neuropathy in
altering foot kinematics, kinetics and plantar pressure (PP) during gait.
Page 11 of 56
Materials and methods: Simultaneous 3-dimensional multisegment foot
kinematics [1], kinetics and PP [2] of healthy and diabetic subjects with
different type of foot were determined. 120 feet were examined (cavus,
valgus heel and hallux valgus): 40 feet in the control group (CG), 80 feet
respectively in the diabetic ((D) and in the neuropathic (N) groups.
Furthermore, subjects were classified according to their foot morphology
and each of the 3 groups was splitted in subgroups: 1. cavus foot,
2. cavus foot and valgus heel, 3. cavus foot and hallux valgus, 4. normal
foot, 5. cavus foot and normally aligned heel, 6. cavus foot and normal
hallux).
Results: D and N subjects of groups 1, 2 and 5 differed significantly
(p<0.05) from CG matched for foot morphology. Most of all D subjects in
groups 1 and 2 were significantly more likely to display lower triplanar
foot subsegments range of motion (especially in midfoot-forefoot dorsiplantarflexion angle) and higher peak PP mainly in correspondence of the
forefoot.
Conclusions: Results indicated the important role of foot morphology in
altering the biomechanics of diabetic subjects.
References
1. Cavanagh PR, Simoneau GG, Ulbrecht JS: Ulceration, unsteadiness, and
uncertainty, the biomechanical consequences of diabetes mellitus. J
Biomech 2003, 26:23-40.
2. Sawacha Z, et al: Characterizing multisegment foot kinematics during
gait in diabetic foot patients. J Neuroeng Rehab 2009, 6:37.
3. Giacomozzi C, et al: The role of shear stress in the etiology of diabetic
neuropathic foot ulcers. J Foot Ankle Res 2008, 1:S1.
O14
Foot and ankle characteristics of children with an idiopathic toe
walking gait
Cylie Williams1,2,3*, Paul Tinley1, Michael Curtin1
1
Charles Sturt University, Albury, NSW, Australia; 2Southern Health, Cardinia
Casey Community Health, Cranbourne VIC, 3977, Australia; 3Peninsula Health –
Community Health, VIC,, 3977, Australia
Background: Idiopathic toe walking (ITW) in children has been associated
with ankle equinus, and while equinus has been linked with foot deformity
in adults, there has been limited investigation on the impact of equinus on
the structural foot change in children.
This study sought to use the weight bearing lunge test [1] and Foot
Posture Index-6 [2] to evaluate the weight–bearing foot and ankle
Figure 1(abstract O13) Results for midfoot-hindfoot inversion-eversion angle in each group from 1 to 6 for CG (yellow), D (red), N (blue).
Page 12 of 56
measures of children with an ITW gait and compare these to their age
matched peers.
Materials and methods: Sixty children between the ages of four and
eight years were grouped into an ITW (N=30) and a non-toe walking
(NTW) (N=30) cohort using a validated ITW tool. The ankle range of
movement and FPI-6 was calculated during appropriate weight–bearing
test and stance.
Results: There was a highly significant difference in the weight–bearing
lunge test measures between the ITW cohort and the NTW cohort. The FPI6 comparison was not significant. The lunge test was also not predictive of
the FPI-6 in the ITW cohort.
Conclusion: Children with an ITW gait demonstrated reduced flexibility at
the ankle joint but had similar weight–bearing foot posture when
compared with NTW children. This shows that for children between the
ages of 4 to 8 years, an ITW gait style impacts on the available dorsiflexion
of the ankle but not the weight–bearing foot posture.
References
1. Bennell K, Khan KM, Matthews B, De Gruyter M, Cook E, Holzer K, Wark JD:
Hip and ankle range of motion and hip muscle strength in young
female ballet dancers and controls. Brit J SportsMed 1999, 33:340-346.
2. Redmond A, Crosbie J, Ouvrier R: Development and validation of a novel
rating system for scoring standing foot posture: The Foot Posture Index.
Clin Biomech 2006, 21:89-98.
O15
Preliminary study of regionalised centre-of-pressure analysis in patients
with juvenile idiopathic arthritis
Gordon J Hendry1,2*, Danny Rafferty1, Ruth Semple1,
Janet M Gardner-Medwin3, Debbie E Turner1, James Woodburn1
1
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow,
Lanarkshire, G4 0BA, UK; 2University of Western Sydney, Sydney, NSW, Locked
Bag 1797, Australia; 3University of Glasgow, Glasgow, Lanarkshire, G12 8QQ, UK
Methods: Fourteen patients with JIA (10 female, 4 male) with a mean age
of 12.4 years (SD 3.2), and 10 controls (6 female, 4 male) with a mean age of
12.5 years (SD 3.4) were studied. Foot deformity and impairment scores
were recorded using the Structural Index (SI) [4] and the Juvenile Arthritis
Foot Disability Index (JAFI) [5]. The progression of the centre of pressure
through the left foot, heel, midfoot, forefoot and toe regions was measured
using an EMED-X pressure platform. Variables analysed were the average
and maximum velocity, velocity at 50% foot length, and the duration of the
centre of pressure. Mean differences between groups and 95% confidence
intervals (CI) were calculated using the t-distribution.
Results: In the JIA group, participants exhibited mild-to-moderate levels
of foot impairments, and mild levels of forefoot deformities. No
significant differences were observed between group means for all CoP
variables (table 1). A trend towards a slower VCoPave at the midfoot in
the patients with JIA was observed.
Conclusions: Foot impairment and deformity scores may represent residual
disease impairments that do not appear to profoundly affect foot function.
The low levels of forefoot deformity in the JIA group may explain the lack of
compensatory off-loading strategies observed. Sub-classification of patients
by locality of symptoms in future studies may be useful to determine the
clinical utility of centre-of-pressure analysis in this patient population.
References
1. Brostom E, Haglund-Akerlind Y, Hagelberg S, Cresswell AG: Gait in children
with juvenile chronic arthritis. Scand J Rheumatol 2002, 31:317-23.
2. Dhanendran M, Hutton W, Klenerman L, Witemeyer S, Ansell B: Foot
function in JCA. Rheumatol Rehabil 1980, 19:20-24.
3. Semple R, Turner DE, Helliwell PS, Woodburn J: Regionalised centre of
pressure analysis in patients with rheumatoid arthritis. Clinical
Biomechanics 2007, 22:127-9.
4. Platto MJ, O’Connell PG, Hicks JE, Gerber LH: The relationship of pain and
deformity of the rheumatoid foot to gait and an index of functional
ambulation. J Rheumatol 1991, 18:38-43.
5. Andre M, Hagelberg S, Stenstrom CH: The juvenile arthritis foot disability
index: development and evaluation of measurement properties.
J Rheumatol 2004, 31:2488-93.
Background: Patients with Juvenile idiopathic arthritis (JIA) may exhibit
altered plantar pressure distributions as a result of foot pain and/or
deformities [1,2]. Previous work involving adult patients with rheumatoid
arthritis suggests that altered loading patterns can be characterised by
delayed transfer of the centre-of-pressure to the forefoot [3]. The aim of this
study was to compare centre-of-pressure characteristics in pre-defined areas
of the foot between patients with JIA and children without JIA.
O16
Correlates of calf cramp in children with Charcot-Marie-Tooth disease
Fiona E Blyton1,2*, Monique M Ryan3, Robert A Ouvrier1,4, Joshua Burns1,4
1
Discipline of Paediatrics and Child Health, The University of Sydney,
Westmead, NSW, 2145, Australia; 2Podiatry Program, The University of
Newcastle, Ourimbah, 2258, Australia; 3Neurosciences Department, Royal
Table 1(abstract O15) Mean (standard deviation) of the regionalised CoP variables for the JIA and able-bodied
control groups
Variable
Region
JIA (n=14)
Controls (n=10)
VCoPave (m/s)
Foot
0.28 (0.03)
0.31 (0.05)
0.02 (0.00, 0.05)
Heel
0.27 (0.08)
0.29 (0.10)
0.02 (-0.02, 0.08)
Midfoot
0.42 (0.10)
0.48 (0.08)
0.06 (0.00, 0.12)
Forefoot
Toes
0.22 (0.03)
0.76 (0.48)
0.23 (0.05)
0.69 (0.25)
0.01 (-0.02, 0.03)
-0.06 (-0.40, 0.28)
-0.01 (-0.62, 0.60)
VCoPmax (m/s)
DCoP (% stance)
VCoP (m/s)
Mean difference (95% CI)
Foot
1.39 (0.77)
1.38 (0.60)
Heel
0.59 (0.14)
0.65 (0.17)
0.06 (-0.07, 0.19)
Midfoot
0.63 (0.32)
0.66 (0.09)
0.03 (-0.18, 0.25)
Forefoot
0.83 (0.42)
0.86 (0.33)
0.03 (-0.29, 0.36)
Toes
1.23 (0.73)
1.31 (0.57)
0.08 (-0.49, 0.66)
Heel
Midfoot
25.83 (6.96)
20.71 (4.14)
26.01 (6.91)
19.19 (3.63)
0.18 (-5.78, 6.14)
-1.52 (-4.89, 1.87)
Forefoot
46.54 (8.92)
48.20 (7.51)
1.66 (-5.53, 8.85)
Toes
6.92 (3.27)
6.60 (1.22)
-0.32 (-2.58, 1.94)
50% foot length
46.54 (7.28)
45.21 (7.93)
-1.34 (-7.82, 5.15)
VCoPave (m/s): average velocity of the centre of pressure; VCoPmax (m/s): maximum velocity of the centre of pressure; DCoP (% stance): duration of the centre of
pressure; CI: confidence interval.
Page 13 of 56
Children’s Hospital, Parkville, 3052, Victoria; 4Institute for Neuroscience and
Muscle Research, The Children’s Hospital at Westmead, Sydney, NSW, 2145,
Australia
Background: Leg muscle cramps have been identified as the strongest
independent predictor of worse quality of life in Australian children with
Charcot-Marie-Tooth disease Type 1A (CMT1A) [1]. There is no accepted
treatment for cramp in children with CMT and the cause of cramp is not
well understood. Potential therapeutic targets should be carefully
identified to direct clinical trials of interventions.
Materials and methods: 81 children aged 2-16 years with CMT1A were
recruited nationally through the Australasian Paediatric Charcot-Marie-Tooth
Disease Registry [2]. Body size and measures of strength, ankle range, foot
posture, balance, agility, endurance, gait and neurophysiology were
assessed at The Children’s Hospital at Westmead (Sydney) and Royal
Children’s Hospital (Melbourne). Data analysis included Pearson product
moment and Spearman rank correlation coefficients for normally and nonnormally distributed continuous data respectively, and Fischer’s exact test
for dichotomous data. Logistic regression analyses were performed to
identify independent predictors of calf cramp.
Results: Of the 81 children, 26 (32%) reported calf cramp and one child
each reported toe, quadriceps or arm cramp. Calf cramp was associated
(p < 0.05) with older age; presence of hand tremor; stronger foot inversion,
eversion, dorsiflexion and plantarflexion; and better performance in long
jump and 9-hole peg tests. Logistic regression analysis revealed only
increasing age (OR 1.32; 95% CI: 1.11 to 1.58; p = 0.002) and presence of
hand tremor (OR 3.81; 95% CI: 1.18 to 12.56; p = 0.028) as independent
predictors of calf cramp.
Conclusions: Calf cramps are common in children with CMT1A and
worsen with age. This study revealed a previously unrecognised link
between cramp and hand tremor in children with CMT1A. Further
investigation of proposed mechanisms and risk factors common to both
cramp and tremor will contribute to our understanding of these common
complications of CMT1A.
References
1. Burns J, et al: Determinants of reduced health related quality of life in
pediatric inherited neuropathies. Neurology 2010, 75:726-731.
2. Burns J, et al: Establishment of the Australasian paediatric Charcot-MarieTooth disease registry. Neuromuscular Disord 2007, 17:349-350.
O17
Marker-based foot posture assessment in children
Catriona M Kerr1*, Julie Stebbins2, Tim Theologis2, Amy B Zavatsky1
1
Department of Engineering Science, University of Oxford, Oxford, UK;
2
Oxford Gait Laboratory, Nuffield Orthopaedic Centre NHS Trust, Oxford, UK
Background: An ideal measure of foot posture should be repeatable,
representative of foot position, quantitative, objective, comprehensive,
and suited to static and dynamic assessment. The Oxford Foot Model
(OFM) is a clinically tested and validated model [1] used to assess foot
deformity during walking. This study aims to use relevant components of
the OFM to provide a quantitative foot posture assessment method. An
assessment of OFM components which distinguish neutral, flat, and
symptomatic flat feet is presented here.
Materials and methods: A clinical assessment of the lower limbs was
performed on 89 children (14 patients with symptomatic flat foot (SF,
n=28 feet), and 75 volunteers with asymptomatic feet and no known
Figure 1(abstract O17) The box plots of mean angles of a standing
trial found to be statistically different between groups. NN – normal
child, neutral foot; NF – normal child, flat foot; SF – child with
symptoms, flat foot. FF – forefoot, HF – hindfoot, TB – tibia.
pathology; 39 males, 50 females; 4.9 to 17.1 years old). Weightbearing
clinical assessment of the asymptomatic group was used to classify the
foot as normal (NN, n=81) or flat (NF, n=69). Reflective markers were
placed at known locations on the lower limb and foot [1], and were
tracked using a 12 camera Vicon MX system. Mean values of each OFM
Euler angle were calculated during three seconds of quiet standing. Each
Table 1(abstract O17) p-values from ANOVA with Tukey post-hoc tests. Abbreviations described in Figure 1
p-value
HF–TB
dorsiflexion
HF–T B int.
rotation
HF–TB
inversion
FF–TB
dorsiflexion
FF–TB
adduction
FF–TB
supination
FF–HF
dorsiflexion
FF– HF
adduction
FF–HF
supination
0.118
NN & NF
0.999
0.581
*0.000
0.856
0.462
*0.013
0.529
0.069
NN & SF
0.999
0.719
*0.000
0.998
*0.000
*0.001
0.346
*0.000
*0.004
NF & SF
0.997
0.999
*0.004
0.944
*0.000
0.271
0.822
*0.000
0.171
Page 14 of 56
foot was treated as an independent sample and ANOVA tests were used
to assess whether OFM angles differed between groups.
Results and discussion: Five OFM angles were found to be different
between groups (Table 1, Figure 1). The eversion of the hindfoot relative
to the tibia was significantly different between all groups (Figure 1). Foot
descriptions used for grouping are largely based on the degree of
hindfoot eversion so a difference between normal and flat feet could be
expected. The difference between SF and NF may reflect severity. The
forefoot was also more pronated relative to the tibia in the flatfooted
populations (Figure 2-3). This again could be a reflection of the original
classification technique. The increased forefoot abduction relative to the
hindfoot and tibia in the symptomatic population (Figure 4-5) may be a
reflection of a midfoot break associated with more severe flat foot.
Conclusions: Elements of the OFM may be used to assess flat feet. Some
measures have been shown to be associated only with symptomatic flat
foot; these may be important in predicting the future for asymptomatic
flat feet. The method is currently being applied to gait to determine if
the parameters are relevant during walking.
Reference
1. Stebbins J, Harrington M, Thompson N, Zavatsky A, Theologis T:
Repeatability of a model for measuring multi-segment foot kinematics
in children. Gait Posture 2006, 23:401-410.
O18
Reliability of three foot models to examine paediatric gait
Ryan Mahaffey*, Stewart Morrison, Wendy Drechsler, Mary Cramp
School of Health, Sport & Bioscience, University of East London, UK
Background: A variety of multi-segmental foot models have been
produced to examine patterns of foot segmental movement during gait
cycle to identify biomechanical differences between normal and
pathological foot function[1-3]. The reliability of foot models to accurately
describe motion of the foot joints is dependent on the ability of the
examiner to repeatedly apply markers to specific landmarks and the
relevance of models’ segmental descriptions to underlying anatomy.
The aim of this study was to test the reliability of segmental angles
measured by three published foot models during paediatric gait.
Materials and methods: Sixteen children, aged 6 to 12 years old, were
recruited to the study. Marker sets for three foot models 3DFoot[1], Oxford
Foot Model (OFM)[2], and Kinfoot[3] were applied to their right feet
simultaneously which to the authors knowledge, is the first direct
comparison of the three models during gait. Each foot model was assessed
for repeatability of maximal joint angle and range of motion during the
gait cycle between two testing occasions. Absolute angular differences and
standard error of measurement (SEM) are reported.
Results: Repeatability of all maximal segmental angles and range of
motions were higher in 3DFoot compared to OFM and Kinfoot (Table 1).
Conclusion: Decreased measurement error observed in 3DFoot and
Kinfoot models may be attributable to normalisation of kinematics data to
subject standing position. In the OFM, non-normalisation of gait data
resulted in variable segmental offsets, particularly in the frontal plane.
Greater measurement error was observed for several foot segments in the
Kinfoot model. This may be due to discrepancies in model segment
definitions in relation to the underlying joint anatomy, especially around
the midfoot to hindfoot segments. 3Dfoot model consistently showed the
least measurement error in the segment motions examined and thus is
appropriate for use to examine foot biomechanics in gait.
Page 15 of 56
Table 1(abstract O18) Inter-session repeatability of foot model’s 3D maximal segmental angles over the gait cycle
Model
Segments
Maximal joint angle
Range of joint angle
° Difference
SEM °
° Difference
SEM °
OFM
Hindfoot to Shank
2.1 ± 15.1
10.9
1.2 ± 8.0
5.7
3DFoot
Hindfoot to Shank
1.0 ± 5.2
3.6
1.0 ± 4.6
3.3
Kinfoot
Hindfoot to Shank
1.0 ± 5.1
3.6
1.4 ± 6.3
4.3
3DFoot
Midfoot to Hindfoot
0.8 ± 3.5
2.2
0.3 ± 2.7
1.9
Kinfoot
Midfoot to Hindfoot
3.0 ± 11.1
6.7
3.7 ± 11.3
6.6
OFM
Metatarsals to Hindfoot
0.8 ± 8.5
5.3
1.3 ± 5.7
5.4
3DFoot
Kinfoot
Metatarsals to Midfoot
Metatarsals to Midfoot
0.7 ± 4.0
2.8 ± 7.8
2.9
4.8
0.6 ± 3.6
2.6 ± 6.6
2.5
3.7
OFM
Hallux to Metatarsals
2.3 ± 15.6
11.2
0.4 ± 13.7
9.1
3DFoot
1.5 ± 10.0
6.2
0.4 ± 12.6
8.8
Kinfoot
4.4 ± 21.8
15.1
2.1 ± 11.8
7.2
References
1. Leardini A, Benedetti M, Berti L, Bettinelli D, Nativo R, Giannini S: Rear-foot,
mid-foot and fore-foot motion during the stance phase of gait. Gait
Posture 2007, 25:453-462.
2. Carson M, Harrington M, Thompson N, O’Connor J, Theologis T: Kinematic
analysis of a multi-segment foot model for research and clinical
applications: a repeatability analysis. J Biomech 2001, 34:1299-2307.
3. MacWilliams B, Cowley M, Nicholson D: Foot kinematics and kinetics
during adolescent gait. Gait Posture 2003, 17:214-224.
O19
Effect of thong style flip-flops on children’s midfoot motion during gait
Angus Chard1*, Andrew Greene1, Adrienne Hunt1, Benedicte Vanwanseele2,
Richard Smith1
1
Exercise and Sport Science, University of Sydney, Sydney, NSW, 1825
Australia; 2Department of Biomedical Kinesiology, Katholieke Universiteit Bus
5005 3000 Leuven, Belgium
Background: Thong style flip-flop footwear (TH) and sandals are the
preferred footwear of 22% of Australian children, however little is known
about the effects of wearing TH on the growing child [1]. Previous
research has shown TH reduces children’s hallux dorsiflexion prior to
contact during walking and jogging and at toe-off whilst jogging [2].
Adult studies have shown TH alters barefoot motion with reduced
eversion [3] and reduce peak plantar-pressure at the hallux, metatarsal
heads and calcaneus [4].The influence of TH on children’s midfoot
kinematics may have important ramifications for children’s developing
feet. This study aims to describe the effect of TH on children’s midfoot
motion during walking and jogging.
Materials and methods: Seven healthy children, mean age 10.47±1.98
years were recruited from Sydney Australia. Participants conducted five
walking trials and five jogging trials while barefoot and wearing TH in
random order. A fourteen camera, three-dimensional motion analysis
system was used to collect kinematic data. Markers located at navicular,
first and fifth metatarsal phalangeal joints, hallux and a rearfoot wand,
defined three foot segments: rearfoot, forefoot and hallux. The midfoot
joint was defined as the articulation between rearfoot and forefoot
segments.
Results: A repeated measure ANOVA found no significant effect of
thongs while walking when compared to barefoot although a trend was
seen towards a more dorsiflexed, everted and abducted midfoot.
A significant effect of TH while jogging was seen during propulsion in the
frontal plane (Figure 1) with the forefoot more inverted (P=0.016) in the
Figure 1(abstract O19) Mean midfoot frontal plane range of motion data from -10% to +10% of the stance phase of gait for barefoot ( red) and thongs
(blue), including ± 95% CI. Contact, midstance and propulsion phases are defined by vertical dashed lines.
TH condition -4.5±6.3SD compared with BF 3.8±5.0SD at toe-off, while
sagittal and transverse planes were not significantly different.
Conclusions: During the propulsive phase significantly greater forefoot
inversion was seen while jogging wearing TH. Results reported are early
findings of an ongoing project. With greater participant numbers the
trends of greater forefoot extension, eversion and abduction while
walking may become significant.
References
1. Penkala S: Footwear choices for children: knowledge, application and
relationships to health outcomes. Sydney, University of Sydney.
2. Chard A, Smith R, et al: Effect Thong Style Flip-Flop Footwear On
Children’s Hallux Sagittal Plane Motion During Gait. ISBS Brussels, Belgium
2011.
3. Shroyer J, et al: Effect of Various Thong Flip-flps on Pronation and
Eversion During Midstance. ACSM Confrence Baltimore, Maryland, USA
2010.
4. Carl TJ, Barrett SL: Computerized analysis of plantar pressure variation in
flip-flops, athletic shoes, and bare feet. J Am Podiatr Med Assoc 2008,
98:374-378.
O20
Three-dimensional ankle kinematics in children’s school shoes during
running
Caleb Wegener1*, Damien O’Meara2, Adrienne E Hunt1, Joshua Burns3,
Benedicte Vanwanseele4, Andrew Greene1, Richard M Smith1
1
Discipline of Exercise and Sports Science, Faculty of Health Sciences, The
University of Sydney, NSW, 1825, Australia; 2New South Wales Institute of
Sport, Sydney, NSW, 2129, Australia; 3Faculty of Health Sciences, The
University of Sydney / Institute for Neuroscience and Muscle Research, The
Children’s Hospital at Westmead, Sydney, NSW, 2145, Australia; 4Research
Centre for Exercise and Health, KULeuven, Leuven, Belgium / Chair Health
Innovation and Technology, Fontys University of Applied Sciences,
Eindhoven, Netherlands
Background: Children are more active during the school day than at
other times [1] and because school shoes are required as part of a
uniform in many countries research on school shoes is required. This
study aimed to determine the effect of school shoes on the ankle joint
complex motion of children while running.
Materials and methods: Twenty children (mean age 9 years (SD2.3))
performed five running trials at a self-selected velocity barefoot and
wearing school shoes (Daytona, Clarks) in a random order. A 14 camera
200Hz motion analysis system (EVaRT5.0, MAC) was used to calculate
marker trajectories. Markers were attached to the right leg and a cluster
wand was attached to the calcaneus through a window in the shoe.
A standing reference trial was used to embed segment axes and then
calculate ankle joint complex motion. Force plate data were collected at
1000Hz (Kistler™). Data were normalised to the stance phase and subphases partitioned from the anterior/posterior force data as: loading
(initial-contact – maximum-negative force); mid-stance (maximumnegative force – zero) and propulsion (positive force – toe-off).
Results: Shoes delayed the maximum-posterior force (22.8% to 29.3%;
p<0.0001) and the zero crossing of the anterior-posterior force (41.1% to
43.6%; p=0.021). During loading shoes increased ankle range of motion
(ROM) in the sagittal (9.9° to 13.8°; p=0.007) and transverse planes (5.7° to
7.7°; p=0.007). During midstance shoes decreased ankle frontal plane
ROM (3.7° to 2.8°; p=0.037). During propulsion shoes increased ankle ROM
in the sagittal plan (30.3° to 33.3°; p=0.018) and decreased frontal plane
ROM (14.4° to 12.0°; p=0.042). Overall stance phase sagittal plane ROM
increased in shoes (31.2° to 34.2°; p=0.034).
Conclusions: This study shows that school shoes increase sagittal ankle
motion during loading and propulsion, but decrease frontal plane motion
during mid-stance and propulsion. These findings will assist in
harmonising school shoe design with foot function.
Reference
1. Page A, Cooper AR, Stamatakis E, Foster LJ, Crowne EC, Sabin M, Shield JP:
Physical activity patterns in nonobese and obese children assessed
using minute-by-minute accelerometry. Int J Obes (Lond) 2005,
29:1070-1076.
Page 16 of 56
O21
Altering gait by way of stimulation of the plantar surface of the foot:
the immediate effect of wearing textured insoles in older fallers
Anna L Hatton1*, John Dixon2, Keith Rome3, Julia L Newton4, Denis J Martin2
1
Department of Physiotherapy, The Princess Alexandra Hospital, Brisbane,
Queensland 4102, Australia; 2Health and Social Care Institute, Teesside
University, Middlesbrough, Teesside, TS1 3BA, UK; 3Health & Rehabilitation
Research Institute, AUT University, Auckland 1020, New Zealand;
4
Institute for Ageing and Health, University of Newcastle,
Newcastle-upon-Tyne, NE1 4LP, UK
Background: Textured surfaces and shoe insoles can alter standing
balance in healthy older adults [1,2] by way of enhanced plantar tactile
stimulation. However, it remains unknown whether textured insoles have
a similar effect on dynamic balance performance during walking in older
people prone to falling. This study explored the immediate effect of
textured insoles on gait measurements in older fallers.
Materials and methods: 26 older adults (19 women; mean [1SD] age
79.0 [7.1] years) with a self-reported history of ≥ 2 falls in the previous
year, conducted tests of level-ground walking over 10m (GaitRITE system),
under two conditions: wearing (in their usual footwear) textured insoles
and smooth (control) insoles. Gait measurements included velocity,
cadence, step length, stride length, base of support, step time, cycle time,
swing time, stance time, and single- and double-limb support times.
Results: Paired-samples t-tests showed significant reductions in gait
velocity (P=0.016) and stride length (left P=0.028, right P=0.043) when
wearing textured insoles. Mean (95% CI) differences were: gait velocity
-4.20 (-7.55 to -0.85) cm.s-1, left stride length -2.92 (-5.49 to -0.34) cm,
right stride length -2.87 (-5.64 to -0.09) cm. No significant differences
were found for the other gait measures.
Conclusions: Stimulating the plantar surface of the foot by way of
wearing this type of textured insole causes an immediate effect - in this
case a slower, more cautious gait in older fallers. Further work is required
to determine how textured insoles can be used to improve gait in older
fallers.
References
1. Palluel E, Nougier V, Olivier I: Do spike insoles enhance postural stability
and plantar-surface cutaneous sensitivity in the elderly? Age 2008,
30:53-61.
2. Hatton A, Dixon J, Martin D, Rome K: Standing on textured surfaces:
effects on standing balance in healthy older adults. Age Ageing 2011,
40:363-368.
O22
Long term whole body vibration training has no effects on plantar foot
sensitivity and balance control
Günther Schlee*, Thomas L Milani
Department of Human Locomotion, Chemnitz University of Technology,
Chemnitz, 09126, Germany
Background: Below-threshold vibration together with low-level
mechanical noise (stochastic resonance) is known to have positive effects
on plantar foot sensitivity and balance control [1]. However, the effects of
above-threshold stimulation on both variables are still not proved. The
goal of this study was to investigate the effects of whole body vibration
(WBV) training, characterized by above threshold stimulation, on plantar
foot sensitivity and balance control of young healthy subjects.
Materials and methods: 38 subjects of both genders were divided in
training (WBV, n=27) and control (CG, n=11) groups. Plantar foot vibration
sensitivity and balance were measured before and after a 6-week WBV
training, in which subjects were exposed weekly to three bouts of
vibration stimuli (27 Hz vibration frequency; 2 mm horizontal amplitude),
with duration from 5.30 up to 8.30 min. Vibration sensitivity was measured
at the heel, first and fifth metatarsal heads and hallux of both feet. Balance
was measured with subjects standing on one leg (right and left legs)
during 20 s with eyes open. Vibration thresholds [µm] and CoP excursion
Page 17 of 56
O23
Plantar foot vibration thresholds: a comparison between measurements
with seated and standing subjects
AMC Germano*, G Schlee, TL Milani
Department of Human Locomotion, Chemnitz University of Technology,
Chemnitz, Germany
Figure 1(abstract O22) Thresholds [μm] at the Hallux: right foot.
Background: The importance of the somatosensory information from the
plantar foot area for balance control is well reported in the literature.
Usually, tests for touch and vibration sensitivity are performed with
subjects in sitting or supine position [1]. However, balance tests are
measured in standing position [2]. Therefore the aim of this study was to
compare vibration thresholds measured with subjects seated and during
standing.
Materials and methods: Sixty-six healthy subjects of both genders with
a mean age of 22.1 (± 3.2) years participated in this study. Vibration
perception thresholds [µm] were measured at 200Hz in two conditions:
sitting (90 ° knee angle) and standing on both legs. Five measurements
with increasing amplitude were performed at each of the three analyzed
anatomical locations of the right plantar foot: heel, first metatarsal head
(MET I) and hallux. The contact force between the vibration probe and
the anatomical locations as well as foot temperature were controlled
throughout the experiments. Body position and anatomical locations
were randomized between the subjects.
Results: The contact forces between the probe and the location were
higher for standing in comparison to sitting condition (27, 7% hallux, 43,
2% Met I and 62, 6% Heel). However, no significant differences in
vibration thresholds between standing and sitting conditions were found
in any of the analysed anatomical locations (Figure 1).
Conclusions: Cassella et al. (2000) demonstrated that greater contact
forces between the probe and the location being analysed are reducing
vibration thresholds. However, despite the higher force applied by the
probe during standing, no significant differences between the tested
positions were evaluated in the present study. It seems that the standing
position affects the perception of vibration stimuli, since subjects need to
concentrate on different tasks, e.g. keep their balance. This could explain
the lack of differences between thresholds measured in the different
positions, although contact forces increased during standing.
References
1. Dietz V: Human neuronal control of automatic functional movements:
interaction between central programs and afferent input. Physiol Rev
1992, 72:33-69.
2. Chiang JH, Wu G: The influence of foam surfaces on biomechanical
variables contributing to postural control. Gait Posture 1997, 5:239-245.
3. Cassella JP, Ashford RL, Kavanagh-Sharp V: The effect of applied pressure
in the determination of vibration sensitivity using the neurothesiometer.
The Foot 2000, 10:27-30.
Figure 2(abstract O22) CoP excursions [mm]: right leg.
[mm] before and after training were compared with a Wilcoxon Test
(a=.05).
Results: No significant differences in vibration thresholds at all measured
locations of both feet (fig. 1 shows data for the right Hallux) were found
after WBV training for both groups. Similar results were evaluated for CoP
excursions measured during standing with the right (fig. 2) and left legs.
Conclusions: Whereas short term WBV training is shown to reduce
plantar foot sensitivity but increase balance control [2], no effects of long
term training could be seen. This may be due to adaptation effects to the
linear, above-threshold stimulation characteristics of this kind of training.
WBV seems not to be an adequate strategy to improve foot sensitivity or
balance control of young healthy subjects.
References
1. Khaodhiar L, et al: Enhancing sensation in diabetic neuropathic foot with
mechanical noise. Diabetes Care 2003, 26:3280-2383.
2. Schlee G, Reckmann D, Milani TL: Whole body vibration training reduces
plantar foot sensitivity but improves balance control of healthy subjects.
Neurosci Lett 2012, 506:70-73.
Figure 1(abstract O23) Vibration thresholds for the standing and sitting
conditions.
O24
Acute effects of whole body vibration on foot sole sensitivity and
plantar pressures during gait initiation
Martin Alfuth, Anne Beiring, Dieter Klein, Dieter Rosenbaum*
Movement Analysis Laboratory, Institute of Experimental Musculoskeletal
Medicine (IEMM), University Hospital Muenster (UKM), Domagkstr. 3, 48149
Muenster, Germany
Background: Sensory receptors in the skin of the foot sole show a sitespecific sensitivity to local pressures and vibrations [1] and provide
feedback during foot loading activities. Impaired plantar feedback has
been shown to affect plantar pressures and kinematics during gait [2-5].
The present study investigated the acute effects of whole body vibration
on plantar sensitivity and foot loading during gait.
Materials and methods: Fifteen healthy subjects (28.4 ± 4.4 years) were
tested before and after 3 minutes of whole body vibrations at a frequency
of 30 Hz (bilateral stance on a Galileo® Med M Plus vibration trainer with
slightly bent knees). Semmes-Weinstein monofilaments were used to test
plantar sensitivity to light touch at the hallux and the heel. Plantar
pressures during gait initiation were recorded using an EMED-ST4 platform.
Results: Plantar sensitivity thresholds were significantly increased after
whole body vibration (p < 0.025), i.e. a decreased plantar sensitivity was
observed under the heel (5.8%) and the hallux (7.1%; Fig. 1). No
significant changes were found in plantar pressure parameters during
gait initiation.
Conclusions: In conclusion, high-intensity whole-body vibration affects
plantar sensitivity by slightly increasing the sensory perception
thresholds. However, this decrease in plantar feedback does not seem to
be functionally relevant with respect to foot loading during gait initiation.
References
1. Hennig EM, Sterzing T: Sensitivity mapping of the human foot. Foot Ankle
Int 2009, 30:986-991.
2. Eils E, Behrens S, Mers O, Thorwesten L, Volker K, Rosenbaum D: Reduced
plantar sensation causes a cautious walking pattern. Gait Posture 2004,
20:54-60.
3. Eils E, Nolte S, Tewes M, Thorwesten L, Volker K, Rosenbaum D: Modified
pressure distribution patterns in walking following reduction of plantar
sensation. J Biomech 2002, 35:1307-1313.
4. Nurse MA, Nigg BM: The effect of changes in foot sensation on plantar
pressure and muscle activity. Clin Biomech (Bristol, Avon) 2001, 16:719-727.
5. Nurse MA, Nigg BM: Quantifying a relationship between tactile and
vibration sensitivity of the human foot with plantar pressure
distributions during gait. Clin Biomech (Bristol, Avon) 1999, 14:667-672.
Page 18 of 56
O25
Foot loading of an African population
Niki M Stolwijk1*, Jacques Duysens1,3, Jan-Willem K Louwerens2,
Noel LW Keijsers1
1
Department of RD&E, Sint Maartenskliniek, Nijmegen, the Netherlands;
2
Orthopaedics, Sint Maartenskliniek, Nijmegen, the Netherlands;
3
Research Center for Movement Control and Neuroplasticity, Department of
Biomedical Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium
Background: In contrast to western countries, foot complaints are rare in
Africa. This is remarkable, as most Africans load their feet significantly
more; they walk many hours each day, often barefoot or with worn-out
shoes. The reason why Africans can withstand such loading without
developing foot complaints might be related to the way the foot is loaded.
Therefore, foot shape and dynamic plantar pressure distribution of an
African population was compared to a Caucasian population.
Materials and methods: The plantar pressure distribution of 77 persons
from Malawi (Blantyre and surroundings) and 77 Dutch persons were
measured using a USB (in Malawi) and 3D (in the Netherlands) Foot Scan®
pressure plate (Rsscan Int.). None of the subjects reported foot complaints.
The normalized [1] mean pressure (MP), peak pressure (PP) and pressuretime integral (PTI) as well as the Arch Index (AI) and the trajectory of the
centre of pressure (COP) during the stance phase were calculated and
compared between both groups. Standardized pictures were taken from
the feet to assess the medial arch angle.
Results: The MP, PP and PTI were significantly higher under the midfoot
and lower under the heel and metatarsal head II and III for the Malawian
group (p<0.007). Furthermore the AI was significantly higher in the
Malawian group (mean 0.28 (SD 0.03) compared to the Dutch group (mean
0.21 (SD 0.06). The COP trajectory was situated more anteriorly during the
first and last part of stance and more posteriorly during the middle part of
the stance phase. In the Malawi group, the medial arch angle was
significantly larger (p<0.05).
Conclusions: Africans have a different loading pattern compared to
Caucasians, with less loading on the forefoot and heel and more
contribution of the midfoot and toes during the roll off. This loading
pattern generates a more equal distribution of pressure, which might help
to prevent for foot complaints.
Reference
1. Keijsers NL, Stolwijk NM, Nienhuis B, Duysens J: A new method to
normalize plantar pressure measurements for foot size and progression
angle. J Biomech 2009, 42:87-90.
Figure 1(abstract O24) Boxplots with plantar sensitivity thresholds of the hallux and the heel before and after whole body vibration (*p < 0.025).
O26
Influence of gastrocnemius-soleus muscle force on sub-MTH load
distribution
Wen-Ming Chen1*, Victor Phyau-Wui Shim2, Taeyong Lee1
1
Division of Bioengineering, National University of Singapore, Singapore;
2
Department of Mechanical Engineering, National University of Singapore,
Singapor
Background: The gastrocnemius-soleus (G-S) muscle complex, the most
dominant extrinsic plantar flexor, plays an important role in the normal
weight-bearing function of the foot. The stability and stance-phase
placement of the foot can be adversely affected when muscular loads/
support are abnormal (e.g. equinus contracture) [1]. This study aims to
formulate a three-dimensional musculoskeletal finite element (FE) model
of the foot to quantify the influence of G-S muscle force on forefoot
metatarsal head (MTH) load distribution.
Materials and methods: The FE model established corresponds to a
muscle-demanding posture in heel-rise, with simulated activation of major
extrinsic plantar flexors. In a baseline case, the required muscle forces were
inversely determined from what would be necessary to generate the
targeted ground reaction forces corresponding to known boundary
conditions. This baseline model served as a reference for subsequent
parametric analysis. The adaptive changes of the foot mechanism (i.e.,
internal joint configurations and plantar loads distributions) in response to
decreased muscle forces in G-S complex (adjusted in a step-wise manner)
were analyzed. The muscle force adjustments mimic effects of surgical
tendo-Achilles lengthening procedure [2].
Results: Movements of the ankle and metatarsophlageal joints, as well as
the forefoot plantar pressure peaks and the pressure distribution under the
metatarsal heads were all found to be extremely sensitive to reduction in
the muscle load in the G-S complex. A 40% reduction in G-S muscle
stabilization can result in dorsal-directed rotations by 8.81° at the ankle
and decreased metatarsophalangeal joint extension by 4.65° (Figure 1).
Page 19 of 56
The resulting peak pressure reductions at individual MTHs, however, may
be site-specific and possibly dependent on foot structure, such as intrinsic
alignment of the metatarsals.
Conclusions: The relationships linking muscular control, internal joint
movements, and plantar loading distributions are envisaged to have
important clinical implications on tendo-Achilles lengthening procedures,
and to provide surgeons with an understanding of the underlying
mechanism for relieving forefoot pressure in diabetic patients suffering
from ankle equinus contracture.
References
1. Sutherland DH, Cooper L, Daniel D: The role of the ankle plantar flexors
in normal walking. J Bone Joint Surg 1980, 62:354-63.
2. Maluf KS, et al: Tendon Achilles lengthening for the treatment of
neuropathic ulcers causes a temporary reduction in forefoot pressure
associated with changes in plantar flexor power rather than ankle
motion during gait. J Biomech 2004, 37:897-906.
O27
Scalpel debridement has minimal effects on painful plantar calluses in
older people: a randomised trial
Karl B Landorf1,2*, Adam Morrow1, Martin J Spink2, Chelsey L Nash1,
Anna Novak1, Adam R Bird1,2, Julia Potter3, Hylton B Menz2
1
Bundoora, Victoria, 3086, Australia; 2Musculoskeletal Research Centre, Faculty
of Health Sciences, La Trobe University, Bundoora, Victoria, 3086, Australia;
3
Faculty of Health Sciences, University of Southampton, Southampton, SO17
1BJ, UK
Background: Plantar calluses are often associated with increased plantar
pressure and foot pain, which can have a detrimental impact on the
mobility and independence of an older person. Scalpel debridement is a
key management strategy for painful calluses; however the effectiveness
Figure 1(abstract O26) Changes in plantar pressure distribution for different angles at ankle and MTP joints in response to reduction of the
gastrocnemius-soleus muscle force.
Page 20 of 56
of this treatment in older people has not been rigorously investigated.
The aim of this randomised trial was to evaluate the effectiveness of
scalpel debridement in reducing plantar pressure and pain associated
with forefoot plantar calluses.
Materials and methods: Eighty participants aged 65 years and older
with painful forefoot plantar calluses were recruited. Participants were
randomly allocated to one of two groups: (i) normal scalpel debridement
or (ii) sham (control) scalpel debridement. Participants were followed for
six weeks. Both participants and assessors were blinded to the
intervention. The primary outcomes measured were the difference
between groups in pain (100 mm VAS) and barefoot plantar pressure
(MatScan® System).
Results: Both groups experienced large decreases in pain following
intervention (up to a 41.9 mm decrease in pain on a VAS). A systematic,
but small beneficial effect on pain was noted in favour of the normal
scalpel debridement group immediately post-debridement to 4 weeks post
debridement (from 6.0 to 7.2 mm ANCOVA adjusted mean difference
between groups). These values, however, are unlikely to be clinically
important to a patient and there were no statistically significant
differences (P<0.05) at any of the primary endpoints (immediately, and at
1, 3 and 6 weeks post-debridement). There were no statistically significant
differences in plantar pressure between the two groups at any time-points.
Conclusions: The findings of this trial indicate that scalpel debridement
of painful plantar calluses has minimal effect. While we found a
systematic effect favouring scalpel debridement, the benefits were small
and not statistically significant. There was no change in plantar pressure
following scalpel debridement.
O28
Velocity of centre of pressure as a predictor of walking speed
Noël LW Keijsers1*, Niki M Stolwijk1, Jan-Willem K Louwerens2, Jaak Duysens1,3
1
Department of RD&E, Sint Maartenskliniek, Nijmegen, the Netherlands;
2
Orthopaedics, Sint Maartenskliniek, Nijmegen, the Netherlands; 3Research
Center for Movement Control and Neuroplasticity, Department of Biomedical
Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium
Background: Walking speed is one of the best measures of overall
walking ability. In plantar pressure measurements, walking speed is usually
assessed using a stopwatch, photocells, or camera systems. As a simple
alternative, contact time can be used but contact time and walking speed
are only moderately correlated. Because walking speeds alters foot
loading, the centre of pressure might be of more value to indicate walking
speed. Therefore, the purpose of this study is to assess walking speed
using the velocity of the centre of pressure (VCOP).
Materials and methods: Thirty-three subjects (range 19-77 years) walked
over a Foot Scan pressure plate (Rsscan Int) at three speed conditions;
slow, preferred, and fast. Contact time and mean VCOP during stance were
calculated for each subject and condition. Walking speed was measured by
a Vicon motion analysis system using a marker on the heel. Linear
regression analysis was used to indicate the relation between walking
speed and the independent variables: contact time, mean VCOP during
stance, and both combined for all walking conditions separately and
together. Finally, stance phase was divided in 5 equal time frames; the
mean VCOP was calculated for each frame and used as 5 independent
variables (5 VCOP)
Results: When all walking speeds were combined, walking speed was
highly correlated with mean VCOP and contact time (see Table 1).
However, correlation coefficients values were much lower for the
Table 1(abstract O28) Correlation coefficient values (r)
Walking speed
Mean VCOP
Contact time
Both
5 VCOP
Slow
0.80
-0.78
0.82
0.84
Preferred
0.90
-0.69
0.90
0.91
Fast
0.60
-0.45
0.61
0.76
All walking speeds
0.94
-0.88
0.94
0.96
preferred, low, and fast walking speed separately. Mean VCOP showed
larger correlation coefficients than contact time. Adding contact time, the
correlation coefficient increased minimally. Walking speed was best
predicted when the 5 VCOP values were used.
Conclusions: Mean VCOP is a better predictor for walking speed than
contact time. Using more detailed information of the VCOP, the
prediction of walking speed can be further increased.
O29
Anatomical plantar pressure masking and foot models: potential for
integration with marker position systems
Claudia Giacomozzi1*, Julie Stebbins2, Alberto Leardini3
1
Dept. of Technology and Health, Italian National Institute of Health (ISS),
Rome, Italy; 2Nuffield Orthopaedic Centre, Oxford, UK; 3Istituto Ortopedico
Rizzoli, Bologna, Italy
Background: Investigation of local foot loading using baropodometry is
highly relevant in both research and clinical settings. In order to reliably
associate local pressure data with foot function and structure, anatomybased masking of footprints is recommended, especially when foot
anatomy or footprints are significantly altered. Previous studies combining
baropodometry with stereophotogrammetry have shown the value of this
methodology in specific, prototype-based situations [1,2]. This study
thoroughly investigates the potential of this method.
Materials and methods: A set of regular footprints from young healthy
volunteers was acquired under controlled conditions by using commercial
3D kinematic tracking systems and pressure mats. The Oxford kinematic
foot model [3] was used for medio-lateral regionalisation of the foot –
clinically relevant for clubfoot and flatfoot –, the Rizzoli model [4] for
longitudinal regionalisation, to clearly distinguish metatarsal from toe or
midfoot loading.
Results: 100 footprints from 20 volunteers have been processed so far for
the Oxford model (processing still ongoing for the Rizzoli model). For
medial and lateral hindfoot, and for medial and lateral forefoot, differences
from a proper geometry-based masking were 3.4-3.9% (vertical force), 0.72.7% (peak pressure), 1.6-4.5% (mean pressure), 2.1-3.8% (area); midfoot
differences rose to 5.2% and 9.7% for peak and mean pressure. However,
none of the differences were statistically significant.
Conclusions: With a correct marker positioning, and an appropriate
calibrated pressure mat (accuracy error <5%, spatial resolution 4sens/cm2),
the method was validated with respect to a proper geometrical selection
(differences <5%). The effect and clinical relevance of lower spatial
resolution, marker positioning errors and use of clusters instead of skin
markers, is also being investigated.
References
1. Stebbins JA, Harrington ME, Giacomozzi C, Thompson N, Zavatsky A,
Theologis TN: Assessment of sub-division of plantar pressure
measurement in children. Gait Posture 2005, 22:372-376.
2. Giacomozzi C, Benedetti MG, Leardini A, Macellari V, Giannini S: Gait
analysis with an integrated system for functional assessment of
talocalcaneal coalition. J Am Podiatr Med Assoc 2006, 96:107-115.
3. Stebbins J, Harrington M, Thompson N, Zavatsky A, Theologis T:
4. Leardini A, Benedetti MG, Berti L, Bettinelli Nativo DR, Giannini S: Rear-foot,
mid-foot and fore-foot motion during the stance phase of gait. Gait
Posture 2007, 25:453-462.
O30
Spatial resolution and peak-pressure-change measurement accuracy
Todd C Pataky
Department of Bioengineering, Shinshu University, Ueda, Nagano, 386-8567,
Japan
Background: It has been suggested that plantar pressures should be
measured at ~6.2 mm to accurately characterize local maxima [1], and it
Page 21 of 56
Figure 1(abstract O29) Projections of marker set onto the footprint obtained by applying the Oxford model (left) and the Rizzoli model (right).
has been shown that sensor widths of 10 mm can cause a 30% pressure
underestimation at the metatarsal heads [2]. However, these results
assume that pressure maxima, not maxima changes, are of primary
interest. The purpose of this study was to examine how spatial resolution
affects accuracy when measuring local maxima vs. changes in local
maxima.
Methods and materials: A pressure pulse model (Figure 1) was
generalized from [2] for force (F) and wavelength (l) as:
f ( x, y ) =
F ⎛
⎛ 2p ⎞ ⎞ ⎛
⎛ 2p ⎞ ⎞
1 + cos ⎜
x ⎟ ⎟ ⎜ 1 + cos ⎜
y⎟⎟
2 ⎜
l ⎝
⎝ l ⎠ ⎠⎝
⎝ l ⎠⎠
(1)
where the maximum pressure (p*) is 4Fl-2, and the measured pressure (p)
has an analytical solution dependent on sensor width w. The measurement
accuracy of local-maxima and local-maxima-changes are p/p* [2], and (p1p2)/(p*1-p*2), respectively, where ‘1’ and ‘2’ denote pulses with different
wavelengths. To mimic insole-padding intervention, where total force is
not expected to change, F was a constant 100 N and l was varied from
20 mm [2]. Numerical optimization was used to find the critical sensor
width that yielded various target accuracies for both local-maxima and a
variety of local-maxima-changes (-100% to +100% change).
Results: Results reveal that a target accuracy of 90% requires 5 mm
resolution for local peak pressures (Figure 2), and that pressure-changes
at 90% accuracy require resolutions of 4.1 mm and 3.2 mm, for changes
of -50% and +50%, respectively. The reason is intuitive: the true
difference pulse has higher frequency components than the original
pulses, so pressure-change accuracy will be lower for all changes >-100%.
Conclusion: This study has shown that, to achieve a given measurement
accuracy, higher spatial resolutions are needed to measure local-pressuremaxima-changes than single-maxima. The main limitations are that
pressure pulses are not, in general, constrained to have constant force
and that broader (i.e. non-local) pressure changes were not considered.
References
1. Davis B, Cothren R, Quesada P, Hanson SB, Perry JE: Frequency content of
normal and diabetic plantar pressure profiles: implications for the
selection of transducer sizes. J Biomech 1996, 29:979-983.
2. Lord M: Spatial resolution in plantar pressure measurement. Med Eng
Phys 1997, 19:140-14.
O31
Biomechanical assessment of children requiring tibialis anterior surgical
tendon transfer for residual congenital talipes equinovarus
Kelly Gray1,2*, Paul Gibbons1,2, David Little1,2, Joshua Burns1,2
1
Department of Orthopaedic Surgery, The Children’s Hospital at Westmead,
Sydney, NSW, 2145, Australia; 2The University of Sydney, NSW, Australia
Introduction: Congenital talipes equinovarus (CTEV) is a deformity in
which the foot is in structural equinus, varus, adductus and cavus and
occurs in approximately 1 per 1000 births [1]. Despite good initial
correction with the Ponseti technique, a tibialis anterior tendon transfer
(TATT) is required in 20-25% of cases to correct residual dynamic
supination observed during gait. Currently, no reliable or valid
biomechanical measures exist to assess the need for, or effectiveness of,
surgery.
Figure 1(abstract O30) Pressure model (Eqn.1). Example pulses of l=20 and 25 mm, with maxima of p*=1000 kPa and 640 kPa, Total force = 100 N.
Page 22 of 56
Figure 2(abstract O30) Critical sensor width needed to achieve given accuracies for local maxima (solid dots), and maxima changes (solid lines).
Materials and method: Between August 2009 to April 2011, 20 children
(average age 53 months ± 10 months) with CTEV were assessed prior to
a TATT. Assessment included range of movement (Dimeglio Scale), foot
alignment in standing (Foot Posture Index), strength (hand held
dynamometry), gait (pedobarography) and function (Clubfoot Disease
Specific Index). These results were compared to 12 children (average age
48 months ± 12 months) with CTEV who did not require a TATT
(controls).
Results: Range of movement and function was significantly less in the
TATT group (p=0.001, p=0.006). The TATT group displayed significantly
greater supination on the Foot Posture Index (p= 0.032) and significantly
less eversion strength compared to the non-surgical group (p<0.001).
During gait, feet of the TATT group had less contact area with ground
(p=0.044), but increased contact time, particularly in the hindfoot
(p=0.001), lateral midfoot (p=0.004) and lateral forefoot (p=0.034).
Pressure-time integral was significantly higher in TATT group for medial
and lateral hindfoot (p=0.027; p=0.010) and lateral midfoot (p=0.034).
Conclusions: Children with CTEV who require a TATT display objective
measureable differences compared to a non-surgical CTEV group. These
measures may be useful in identifying which children require a TATT in the
future.
Reference
1. Dobbs MB, Gurnett CA: Update on clubfoot: etiology and treatment. Clin
Orthop Relat Res 2009, 467:1146-1153.
O32
Plantar pressures and ankle kinematics following anterior tibialis
tendon transfers in children with clubfoot
Kirsten Tulchin1*, Kelly A Jeans1, Lori A Karol1, Lindsey Crawford2
1
Texas Scottish Rite Hospital for Children, Dallas, Texas, 75219, USA; 2John
Peter Smith Hospital, Fort Worth, Texas, 76104, USA
Background: Relapses following nonoperative treatment for clubfoot
occur in 29-37% of feet following initial correction [1]. In patients with
residual clubfoot deformity, excessive medial pull of the anterior tibialis
Table 1(abstract O32) Plantar pressures comparing Pre-Op, Post-Op & Control
Forefoot
Medial
Mean
Midfoot
Lateral
+SD
Mean
Medial
+SD
Mean
+SD
Forefoot
Lateral
Mean
1st Met.
+SD
Mean
+SD
<0.0001 ‡*†
<0.0001 ‡*†
0.0001 ‡*
<0.0001 ‡*
<0.0001 ‡*
Pre
10.2
6.6
10.6
4.8
4.4
2.6
16.2
6.3
4.4
Post
Control
17.2
25.0
11.4
8.2
15.4
20.8
7.1
6.4
6.5
7.5
3.2
2.0
10.0
7.9
3.3
1.8
6.5
7.5
Peak Pressure
+SD
Mean
+SD
<0.0001 ‡*
<0.0001 ‡*
2.6
9.1
3.7
23.8
10.3
3.2
2.0
12.4
14.7
4.6
4.9
16.0
14.5
4.0
4.7
<0.0001 ‡*†
<0.0001 ‡*†
9.1
3.4
13.2
4.8
2.1
2.1
24.8
2.9
2.1
2.1
8.4
2.3
26.6
5.2
Post
10.4
2.3
12.7
2.7
3.8
3.6
20.6
2.6
3.8
3.6
8.4
1.2
22.6
4.8
Control
11.8
1.1
11.7
1.0
5.2
3.4
16.0
2.7
5.2
3.4
8.9
1.5
17.8
2.5
Contact Time%
0.0011 ‡*
0.0012 ‡
Mean
3-5th Mets.
Pre
Contact Area%
0.0011 ‡
2nd Met.
0.3299
0.0408
0.0026 ‡*
<0.0001 ‡†
<0.0001 ‡*
<0.0001 ‡*†
0.5241
0.0006 *
<0.0001 ‡*†
Pre
38.8
21.9
48.2
18.9
31.6
22.7
80.3
8.0
31.6
22.7
75.7
15.1
94.5
3.5
Post
Control
54.4
50.7
17.1
9.0
57.2
49.9
15.0
8.5
47.2
45.2
20.9
9.2
74.6
61.8
9.5
10.8
47.2
45.2
20.9
9.2
86.9
82.0
10.7
6.3
90.9
83.9
5.1
5.0
Significant change (p< 0.05): ‡Pre/Control; †Post/Control; *Pre/Post.
muscle can lead to persistent supination and inversion of the forefoot [1].
The purpose of this study was to assess kinematic and plantar pressure
changes following an ATT transfer.
Materials and methods: Thirty children (37 feet) were evaluated pre- and
2.0±0.6 yrs (range: 0.8 to 2.9) post-op following ATT transfer. Foot
progression angle (FPA) and sagittal ankle kinematics were assessed using a
VICON system. Plantar pressures were collected using the Emed ST Platform.
Representative trials were chosen for each subject for gait and plantar
pressures. Plantar pressures were divided into medial and lateral hindfoot,
midfoot and forefoot. Variables included: contact time (CT%), contact area
(CA% total), peak pressure (PP), hindfoot-forefoot angle [2], deviation of the
center-of-pressure (COP) line and region of initial contact. Twenty age
matched controls were used for comparison.
Results: Changes in plantar measures in the hindfoot show normalization of
the CA% and CT% post-op (Table 1). The forefoot shows the most change
with a significant decrease in CA%, CT% and PP in the lateral forefoot,
redistributed to the first metatarsal for more even distribution through the
foot. Initial contact was not different from normal post-op and no change
was seen in the deviation of the COP line or hindfoot-forefoot angle
(p=0.8025) post-op. Kinematically, patients with greater than 5° internal FPA
had a higher likelihood of a successful outcome (60% had a less internal
FPA, while no feet worsened.) Those that demonstrated a normal FPA preop risked a worsening FPA (35% had a more internal FPA while only 12%
improved.) There were 16/37 (43%) feet with foot drop in late swing pre-op,
10 of which improved following surgery, however, 5 new foot drops
developed post-op.
Conclusions: Changes seen in plantar pressures would suggest that during
stance, the foot is better aligned, more evenly distributing pressures
throughout the foot rather than focused to the lateral midfoot and forefoot
regions. Based on gait results, pre-operative foot progression angle may be
an indicator for successful outcomes of ATT transfer in patients with residual
deformity.
References
1. Richards BS, et al: A comparison of two nonoperative methods of idiopathic
clubfoot correction: the Ponseti method and the French functional
(physiotherapy) method. J Bone Joint Surg Am 2008, 90:2313-2321.
2. Jeans KA, Karol LA: Plantar pressures following Ponseti and French
physiotherapy methods for clubfoot. J Pediatr Orthop 2010, 30:82-89.
O33
Postural control in total knee arthroplasty patients with patellofemoral
pain syndrome before and six months after re-operation
Helena Gapeyeva1*, Tiit Haviko2, Aare Märtson2, Herje Aibast1, Jaan Ereline1,
Mati Pääsuke1
1
Institute of Exercise Biology and Physiotherapy, University of Tartu, Tartu
51014, Estonia; 2Department of Traumatology and Orthopaedics, University
of Tartu, Tartu 51014, Estonia
Background: Although excellent long-term clinical results have been
reported for the total knee arthroplasty (TKA), 37% of patients have limited
functional improvement one year after the surgery [1]. Patients with a clinical
presentation of anterior knee pain could be diagnosed with patellofemoral
pain syndrome (PFPS). Modified clinical classification of PFPS patients
includes two main groups: with malalignment and with muscular dysfunction
[2]. The aim of the study was to compare postural stability characteristics in
TKA patients with PFPS before and six months after re-operation.
Materials and methods: Twelve patients aged 59-77 years with PFPS
following unilateral TKA participated in the study. Pre-TKA, all patients
had primary degenerative knee OA in stage III or IV (Kellgren-Lawrence
Scale) and were scheduled for the first TKA. Duration of pain before TKA
was 9.3±2.5 years and re-operation due to PFPS was performed 18.8±3.5
months later. Patella malalignment was noted in eight patients and
patella altered position in three patients. Static standing balance was
assessed by centre of foot pressure (COP) sway registered during 30 s
quiet bipedal standing with eyes open on twin force plates Kistler 9286A
(Switzerland) using Sway software of motion analysis system Elite (BTS S.
p.A., Italy). Plantar pressure distribution was recorded by Digital Biometry
Scanning System and Milletrix software (DIASU, Italy). Data are means and
standard errors of means (±SE).
Page 23 of 56
Table 1(abstract O33) Plantar pressure distribution
(weight ratio %) in TKA patients with PFPS before and
6 months after re-operation
Characteristics
Before reoperation
After reoperation
p
FOREFOOT PFPS leg
66.37 ± 4.90
51.55 ± 1.64
0.021
64.15 ± 6.47
52.16 ± 3.40
NS
44.85 ± 1.75
51.54 ± 1.86
0.021
49.16 ± 3.36
47.84 ± 3.40
NS
Non-PFPS
leg
REARFOOT PFPS leg
Non-PFPS
leg
Results: COP sway trace radius of PFPS leg was significantly shorter
6 month after re-operation as compared before it (5.91± 0.48 and 4.22 ±
0.22 mm, respectively, p=0.007). No significant difference was found in
COP trace length and velocity as compared pre- and post-surgery data
(p>0.05). Significant decrease of plantar pressure distribution in forefoot
of PFPS leg was noted (p<0.05, Table 1).
Conclusions: Main findings of our study were: (1) postural control in TKA
patients with PFPS significantly improves (and 2) re-distribution of plantar
pressure from forefoot to rearfoot in PFPS leg takes place 6 months after
re-operation. The link between the segmental configuration of the lower
limbs was described [3] and the importance of paying attention to
balancing of the PF soft tissues was emphasized in studies of PF pain
after TKA [4].
Acknowledgements: This study was supported by Estonian Ministry of
Education and Research project No SF0180030s07 and Estonian Science
Foundation project No 7939.
References
1. Franklin PD, Li W, Ayers DC: The Chitranjan Ranawat Award: functional
outcome after total knee replacement varies with patient attributes. Clin
Orthop Relat Res 2008, 466:2597-2604.
2. Witvrouw E, et al: Clinical classification of patellofemoral pain syndrome:
guidelines for non-operative treatment. Ortopedia Biomeccanica,
Riabilitazione Sportiva. 7 Corso Internazionale. Assisi, 21-23 novembre 2003
Universita degli Studi – Azienda Ospedaliera, Perugia 2003, 174-186.
3. Roudiger PR: Relative contribution of the pressure variations under the
feet and body weight distribution over both legs in the control of
upright stance. J Biomech 2007, 40:2477-2482.
4. Scuderi GR, Insall JN, Scott NW: Patellofemoral pain after total knee
arthroplasty. J Am Acad Orthop Surg 1994, 2:239-246.
O34
Fluoroscopic and gait analyses for the assessment of the functional
performance of an original total ankle replacement
Francesco Cenni1, Sandro Giannini1,2, Claudio Belvedere1, Matteo Romagnoli2,
Lisa Berti1, Maddalena Pieri1, Alberto Leardini1*
1
Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, 40136 Bologna,
Italy; 2Department of Orthopedic Surgery, Istituto Ortopedico Rizzoli , 40136
Bologna, Italy
Background: An original total ankle replacement design was developed
with the aim of establishing compatibility between the prosthetic
articulating surfaces and the retained ligaments. This was achieved with a
special shape of a conforming meniscal bearing, free to move forwards/
backwards on both metal components during dorsi/plantar flexion. Careful
kinematics analyses were carried out in patients after this replacement to
assess the functional performance during activity of daily living.
A thorough assessment shall include standard gait analysis (GA) and the
more accurate motion tracking of the components by 3D fluoroscopic
analysis (FA).
Materials and methods: Eleven patients implanted with the BOX Ankle
(Finsbury Orthopaedics, Leatherhead-Surrey, UK) were analyzed at
12 months after surgery. GA was performed during stair-climbing/
descending using a 8-cameras motion system (Vicon Motion Systems,
Oxford, UK), electromyography (ZeroWire, Aurion, Milan, Italy), and an
Page 24 of 56
Table 1(abstract O34) Gait analysis results
Unit
Stair climbing
Stair descending
Operated side
Controlateral side
Operated side
Controlateral side
16.3±4.1
Hip range of flex- extension
[Deg]
59.2±4.1
46.8±6.5
24.1±5.5
Max hip flexion moment
[% BW*h]
7.5±1.2
6.3±1.1
3.2±1.2
5.9±6.7
Knee range of flexion
[Deg]
56.4±6.4
56.5±6.7
79.6±5.7
76.4±5.0
Max knee flexion moment
[% BW*h]
1.9±1.2
5.1±2.6
5.9±1.6
7.7±1.6
Ankle range of flexion
[Deg]
16.8±9.5
38.8±9.8
17.8±6.7
55.5±7.5
Ankle dorsi/plantar flexion at foot strike
[Deg]
5.9±4.3
10.9±6.6
-9.1±5.4
-27.0±6.8
Max ankle dorsi-flexion moment
[% BW*h]
6.8±1.2
7.6±1.3
6.6±1.4
7.8±1.5
established protocol for lower limb joint kinematics and kinetics [1]. For
the same patients and motor tasks, FA was performed on the same day
using a standard fluoroscope (CAT Medical System, Italy) at 10Hz and an
established technique [2], which works out motion of the three
components in the three anatomical planes.
Results: Nearly physiological joint kinematic patterns were observed in both
legs (Table 1). A statistically significant difference between the operated and
controlateral sides were found only in the hip and ankle range of flexion,
and in dorsi/plantar flexion at foot strike (p<0.05). From FA, over all patients,
1.2 and 3.4 mm of antero-posterior meniscal-to-tibial translation were
coupled with 5.2° and 8.2° flexion between the two metal components,
respectively during stair climbing and descending. At the replaced joint, a
significant correlation was found between meniscal-motion from FA and
both range of flexion and flexion at foot-strike from GA.
Conclusions: Nearly normal kinematics and kinetics at the main joints
were observed also at the replaced leg. In addition, nearly natural function
was restored at the replaced ankle, with large coupled motion in the three
anatomical planes. The meniscal-motion was coupled with ankle flexion,
supporting the main claims of the designers.
References
1. Leardini A, et al: A new anatomically based protocol for gait analysis in
children. Gait Posture 2007, 26:560-71.
2. Catani F, et al: In- vivo kinematics and kinetics of a bi-cruciate
substituting total knee arthroplasty: a combined fluoroscopic and gait
analysis study. J Orthop Res 2009, 27:1569-75.
O35
How well can skin marker analysis detect the kinematics of a total
ankle arthroplasty? - a comparison to videofluoroscopy
Renate List1*, Hans Gerber1, Mauro Foresti1, Silvio Lorenzetti1,
Pascal Rippstein2, Edgar Stüssi1
1
Institute for Biomechanics, ETH Zurich, 8093 Zurich, Switzerland; 2Foot and
Ankle Center, Schulthess Clinic, 8093 Zurich, Switzerland
Background: Previous in vivo studies on total ankle arthroplasty (TAA)
kinematics were mainly performed using skin marker analysis, which has
the drawback of skin movement artefacts [1]. A further limitation is the
inaccessibility of the talus for attaching markers, thus the impossibility to
distinguish tibiotalar from subtalar motion. So far it is not known how
well skin marker analysis detects the kinematics of the TAA.
Materials and methods: The kinematics of 11 TAA participants were
simultaneously analysed by skin marker and videofluoroscopic
assessment during level gait (gt), walking up- (uph) and downhill (dnh).
The fluoroscopic data analysis included a 2D/3D registration (error
< 0.2° in-plane, <1.3° out-of-plane) [2]. The markerset consisted of 4
rearfoot and 6 shank markers [3]. For both approaches joint rotations
were described along the axes of the marker based joint coordinate
system. As a descriptor of differentiation the maximal and the root
mean square differences (max diff, RMS diff) between skin marker and
fluoroscopic joint rotations were calculated over the whole stance
phase. Besides, maximal ranges of motion (ROM) were compared using
a paired t-test.
Results: Skin marker analysis significantly overestimated sagittal plane ROM
of the TAA for 5(gt), 6(uph) and 6(dnh) and underestimated for 1(uph) and
2(dnh) subjects. Frontal plane ROM was significantly overestimated for 7(gt),
8(uph) and 9(dnh) of the 11 subjects. Transverse plane ROM was for 2(uph)
and 2(dnh) subjects significantly overestimated, and for 3(gt), 1(uph) and
7(dnh) subjects significantly underestimated by skin markers. For mean RMS
diff, mean max diff and mean ROM see Table 1.
Conclusions: The differences between skin marker assessed rearfootshank and the fluoroscopic assessed isolated TAA motion were neither
consistent between subjects, nor motion planes, nor conditions. For
transverse and frontal plane rotations, the maximal differences were in the
range of the maximal corresponding ROM. Discrepancies for the sagittal
plane were smaller, but still for some subjects, ROM were significantly
different.
References
1. Leardini A, Chiari L, Della Croce U, Cappozzo A: Human movement
analysis using stereophoto-grammetry. Part 3. Soft tissue artifact
assessment and compensation. Gait Posture 2005, 21:212-225.
Table 1(abstract O35) RMS diff and max diff over the whole stance phase and ROM assessed by videofluoroscopy
(fluoro) and skin marker analysis (skin). Mean and SD over all 11 subjects of sagittal (sag), frontal (front) and
transverse (trans) plane rotations, * statistically significant difference between fluoro and and skin (p<0.05)
Sag
Level gait
Front
Trans
Sag
Uphill
Front
Trans
Sag
Downhill
Front
Trans
RMS
diff
[°]
Mean
± SD
1.5
± 0.7
2.0
± 0.9
2.9
± 1.0
1.5
± 0.6
2.4
± 1.4
2.8
± 1.2
1.7
± 0.6
2.0
± 0.9
3.0
± 1.2
Max
diff
[°]
Mean
± SD
3.9
± 1.7
4.9
± 2.5
6.8
± 2.7
3.6
± 1.8
5.1
± 2.8
5.7
± 2.2
4.3
± 1.7
4.5
± 1.9
5.7
± 1.9
Fluoro Skin Fluoro Skin Fluoro Skin Fluoro Skin Fluoro Skin Fluoro Skin Fluoro Skin Fluoro Skin Fluoro Skin
ROM
[°]
Mean
± SD
10.0*
± 2.8
11.6*
±
2.9
2.9*
± 1.0
5.8*
±
2.1
8.1*
± 2.9
6.5*
±
2.7
9.6*
± 4.8
11.5*
±
3.3
2.5*
± 0.7
5.6*
±
2.7
6.6
± 2.3
6.8
±
3.2
13.1
± 3.7
14.7
±
2.7
3.0*
± 0.6
5.4*
±
2.1
7.7*
± 2.5
5.7*
±
2.3
2.
3.
List R, Stacoff A, Foresti M, Gerber H, Stuessi E: An in vivo procedure to
quantify 3D kinematics of ankle arthroplasties using videofluoroscopy.
J Biomech 2008, 41:S321.
List R, Unternährer S, Ukelo T, Wolf P, Stacoff A: Erfassen der Vor- und
Rückfussbewegungen im Gehen und Laufen. Sportmed Sporttraumatol
2008, 56:43-49.
O36
Preliminary marker-based validation of a novel biplane fluoroscopy
system
Joseph M Iaquinto1, Richard Tsai1, Michael Fassbind1, David R Haynor2,
Bruce J Sangeorzan1,3, William R Ledoux1,3,4*
1
VA RR&D Center of Excellence for Limb Loss Prevention and Prosthetic
Engineering, Seattle, WA, 98108, USA; 2Departments of Radiology and
Bioengineering, University of Washington, Seattle, WA, 98195-7117, USA;
3
Department of Orthopaedics & Sports Medicine, University of Washington,
Seattle, WA, 98195-6500, USA; 4Department of Mechanical Engineering,
University of Washington, Seattle, WA, 98195, USA
Background: The use of biplane fluoroscopy to track bones in the foot is
challenging, due to distortion, overlap and image artefact inherent in
fluoroscopy systems and high speed photography. The accuracy and
precision of these systems have been reported [1-4] and are presented
here for our biplane fluoroscopy system.
Materials and methods: Biplane Fluoroscopy System: The system consists
of two Philips BV Pulsera C-arms set in custom frames around a raised floor
with a radiolucent imaging area. X-ray images are captured with high
speed (1000fps) cameras. Validation Object: 1.6mm tantalum beads were
placed in a machined block (wand) then measured to 7 microns with a
Coordinate Measuring Machine to determine their centroid location. The
wand was translated and rotated via a 1 micron precision stepper-motor
for static validation, as well as manually swept through the field of view at
~0.5m/s for dynamic. Static Accuracy and Precision: accuracy was defined
as the RMS error between the translation of the stepper-motor and the
measured movement of the beads; precision is defined as the standard
deviation of the bead locations. For rotation, accuracy was defined as the
RMS error between the applied and measured rotation of the wand.
Dynamic Accuracy and Precision: accuracy was defined as the RMS error
between the known and measured inter-bead distance; precision was the
standard deviation of the inter-bead distance. 3D location processing was
accomplished using custom software written in MatLab to derive the 3D
location of objects from two, time-synchronized, 2D fluoroscopy images of
known spatial relationship. This software also compensates for the image
distortion (Figure 1).
Page 25 of 56
Results: Translation: the overall RMS error was 0.066 mm, with a precision
of ± 0.016 mm. Rotation: the RMS error was 0.125°. Dynamic motion: the
overall RMS error was 0.126 mm, with a precision of ± 0.122 mm.
Conclusions: The accuracies and precision in the results are comparable
to similar such systems in development to investigate other joints of the
body [1-4]. We are currently developing and validating a marker-less
technique for tracking the bones of the foot.
References
1. Brainerd EL, et al: X-ray reconstruction of moving morphology (XROMM):
precision, accuracy and applications in comparative biomechanics
research. J Exp Zool A Ecol Genet Physiol 2010, 313:262-279.
2. Miranda D, et al: Accuracy and precision of 3-D skeletal motion capture
technology. 56th ORS 2010, Paper no. 334.
3. Li G, et al: Validation of a non-invasive fluoroscopic imaging technique
for the measurement of dynamic knee joint motion. J Biomech 2008,
41:1616-1622.
4. Kaptein BL, et al: A comparison of calibration methods for stereo
fluoroscopic imaging systems. J Biomech 2011, 44:2511-2515.
O37
Measurement of longitudinal tibial nerve excursion during ankle joint
dorsiflexion: an in-vivo investigation with ultrasound imaging
Matthew Carroll1,2*, Janet Yau2, Keith Rome1,2, Wayne Hing1,3
1
Health and Rehabilitation Research Institute, AUT University, Auckland, 0627,
New Zealand; 2Department of Podiatry, AUT University, Auckland, 0627, New
Zealand; 3Department of Physiotherapy, AUT University, Auckland, 0627, New
Zealand
Background: A key mechanical function of peripheral nerves is their
ability to slide in relation to the surrounding tissues. This function is of
paramount importance to maintain ideal neural function [1]. Advances in
ultrasound imaging and the development of specific software (crosscorrelation analysis) have made it possible to analyse real-time ultrasound
images, allowing for quantification of in-vivo peripheral nerve movement
[2]. Cross-correlation analysis has been utilised in numerous upper
extremity in-vivo neural investigations [3-5]. No study has investigated invivo longitudinal nerve excursion at the ankle joint. The aims of this study
were to quantify the degree of longitudinal tibial nerve excursion as the
ankle moved from dorsiflexion to plantarflexion and assess the between
session intra-rater reliability of the ultrasound imaging technique.
Materials and methods: A sample of sixteen participants (10 male,
6 female; mean [SD] age 34.7 [9.3] years old) were recruited. A three
second video loop of the tibial nerve was captured by ultrasound
imaging as the ankle moved from 20° plantarflexion to 10° dorsiflexion.
The tibial nerve was imaged on two occasions with a 5 minute interval
Figure 1(abstract O36) Distortion plate before (left) and after (right) correction for pin-hole distortion and magnetic distortion.
Page 26 of 56
between measurement sessions. Foot and ankle position was standardised
on a measurement platform. Video loops were analysed to determine the
degree of longitudinal nerve excursion. Intraclass correlation coefficients
(ICC), with 95% confidence intervals (CI), standard error of the
measurement (SEM) and the smallest real difference (SRD) were calculated
as an indication of reliability and measurement error.
Results: Results demonstrated mean [SD] longitudinal excursion of 3.01
[0.97] mm. The between session intra-rater reliability was excellent
(ICC=0.93; 95% CI, 0.70-0.96), with SEM, 0.26mm and a mean SRD of
0.75mm.
Conclusions: Ultrasound imaging in conjunction with cross correlation
analysis presents a reliable technique to quantify in-vivo tibial nerve
movement during ankle joint dorsiflexion.
References
1. Shacklock M: Clinical Neurodynamics: A new system of musculoskeletal
treatment. Edingburgh: Elsevier 2005.
2. Dilley A, et al: The use of cross-sectional analysis between highfrequency ultrasound images to measure longitudinal median nerve
movement. Ultrasound Med Biol 2001, 27:1211-1218.
3. Erel E, et al: Longitudinal sliding of the median nerve in patients with
carpal tunnel syndrome. J Hand Surg Br 2003, 28:439-443.
4. Dilley A, et al: Quantitative in vivo studies of median nerve sliding in
response to wrist, elbow, shoulder and neck movements. Clin Biomech
(Bristol, Avon) 2003, 18:899-907.
5. Dilley A, Summerhayes C, Lynn B: An in vivo investigation of ulnar nerve
sliding during upper limb movements. Clin Biomech (Bristol, Avon) 2007,
22:774-779.
O38
Reliability of ultrasound to measure morphology of the toe flexor
muscles
Karen J Mickle1,2*, Christopher J Nester1, Gillian Crofts1, Julie R Steele2
1
Manchester, M6 6PU, United Kingdom; 2Biomechanics Research Laboratory,
University of Wollongong, Wollongong, NSW, 2522, Australia
Background: Measuring the strength of individual foot muscles is very
challenging; however, measuring muscle morphology has been shown to
be associated with strength [1]. A reliable method of assessing foot muscle
atrophy and hypertrophy would therefore be beneficial to researchers and
clinicians. Real-time ultrasound (US) is a non-invasive, objective and
inexpensive method of assessing muscle morphology and has been
employed widely to quantify cross-sectional area (CSA) and linear
Table 1(abstract O37) Mean muscle size values taken on
Days 1 and 2 and their respective ICC and Limits of
Agreement (LoA) values
Mean Day 1
(cm)
Mean Day 2
(cm)
ICC
LoA
(cm)
ABH CSA
2.45
2.46
0.98
0.45
ABH thickness
1.25
1.20
0.98
0.26
FHB CSA
2.55
2.55
0.83
0.74
FHB thickness
1.36
1.29
0.94
0.22
FDB CSA
FDB thickness
2.22
1.06
2.32
1.08
0.99
0.87
0.18
0.20
QP CSA
1.92
1.91
0.99
0.17
QP thickness
1.09
1.07
0.95
0.20
ABDM CSA
2.28
2.26
0.97
0.37
ABDM
thickness
1.14
1.10
0.96
0.20
FDL CSA
1.69
1.57
0.99
0.17
FHL
3.58
4.04
0.98
0.51
dimensions of larger muscles (e.g. quadriceps, triceps surae). Few studies,
however, have determined its ability to measure the small muscles of the
foot and ankle. This study aimed to determine whether US is a reliable tool
to measure the morphology of the toe flexor muscles.
Materials and method: The abductor hallucis (ABH), flexor hallucis brevis
(FHB), flexor digitorum brevis (FDB), quadratus plantae (QP) and abductor
digiti minimi (ABDM) muscles in the foot and the flexor digitorum longus
(FDL) and flexor hallucis longus (FHL) muscles in the shank were assessed
in five males and three females (mean age =33.1±11.2 years). Muscles
were imaged using a GE Venue 40 US with either a 6-9 or 7.6-10.7 MHz
probe in a random order, and on two occasions 1-6 days apart. Muscle
thickness and CSA were measured using Image J software with the
assessor blinded to muscle and day of scan. Intraclass correlation
coefficients (ICC) and limits of agreement (LoA) were calculated to assess
day-to-day repeatability of the measurements (Table 1).
Results and conclusion: The method was found to have good reliability
(ICC=0.83-0.99) with LoA between 7.9-29.1% of the relative muscle size.
Although published data is not available for all muscles tested, the LoA
were within the ranges that we may expect for changes in muscle size
due to ageing, disease or intervention. Ultrasound is therefore deemed a
reliable method to measure morphology of the toe flexor muscles.
Reference
1. Gadeberg P, Andersen H, Jakobsen J: Volume of ankle dorsiflexors and
plantar flexors determined with stereological techniques. J Appl Physiol
1999, 86:1670-1675.
O39
In vivo measurement of the biomechanical properties of plantar soft
tissues under simulated gait conditions
Daniel Parker1,2*, Glen Cooper1, Stephen Pearson1, David Howard1,
Gillian Crofts1, Christopher Nester1
1
School of Health Sciences, University of Salford, Salford, Greater Manchester,
M6 6PU, UK; 2Manchester Metropolitan University, Manchester, Greater
Manchester, M15 6BH, UK
Background: In vivo biomechanical properties of plantar soft tissues
have been assessed via manual indentation using simplified loading
profiles [1], or in gait, with low image resolution/capture rates [2]. Since
plantar soft tissue properties are highly rate dependent [3] these
methods are potentially inadequate. The Soft Tissue Response Imaging
Device (STRIDE) permits functionally relevant loading profiles to be
applied to the plantar tissues.
Materials and methods: An Ultrasound probe, Linear Variable Displacement Transducer (LVDT) and load cell were mounted in series within a
cylindrical column. The column was driven vertically by an actuator to
contact the plantar surface of the heel. Drive profiles were generated from
barefoot walking motion data and input to the actuator. Output from the
load cell and LVDT were recorded at 3kHz. Ultrasound images were
recorded at 200Hz. The subject’s leg was braced such that tissue strain of
0.4 (tissue thickness of 10.66mm) was predicted when vertical displacement
of the device peaked. Three trials of 10 cycles were conducted for 1 subject
to assess device motion compared to tissue compression.
Results: Measured vertical displacement (Fig2) matches the input motion
profiles (ICC>0.99) for all cycles. Minor deviation occurred at peak
accelerations (loading/unloading transition) but reduced over multiple
cycles with a final error of +0.19mm (SD, 0.01). The measured tissue
thickness at peak compression was greater (mean, +1.34mm; SD, 0.13)
than the target thickness (10.66mm), however showed a reduction from
12.24mm to 11.85mm after 10 cycles (Fig3).
Conclusions: STRIDE replicated the rapid loading experienced by the
heel during gait. The ultrasound, load cell and LVDT measured the tissue
response to compression. To achieve target strains improved bracing and
multiple compressions are required.
Acknowledgements: This research was financially supported by SSL
International Ltd. Thanks to Paul Busby, University of Salford, for
development support for the STRIDE device. Thanks to Annamaria
Guiotto, University of Padova, for support with protocol development and
testing. Thanks to PhD candidate Hannah Jarvis for supplying the motion
data used to derive input profiles to the STRIDE device.
Page 27 of 56
Figure 1(abstract O39) STRIDE.
Figure 2(abstract O39) Measured vertical displacement.
Figure 3(abstract O39) Tissue thickness at peak compression.
References
1. Zheng YP, Choi YK, Wong K, Chan S, Mak AF: Biomechanical assessment
of plantar foot tissue in diabetic patients using an ultrasound
indentation system. Ultrasound Med Biol 2000, 26:451-456.
2. Wearing SC, Smeathers JE, Yates B, Urry SR, Dubois P: Bulk compressive
properties of the heel fat pad during walking: a pilot investigation in
plantar heel pain. Clin Biomech (Bristol, Avon) 2009, 24:397-402.
3. Hsu C, Tsai W, Chen CP, Shau Y, Wang C, Chen MJ, Chang K: Effects of
aging on the plantar soft tissue properties under the metatarsal heads
at different impact velocities. Ultrasound Med Biol 2005, 31:1423-1429.
O40
How accurately can surface markers be placed on bony landmarks of
the foot?
Alpesh Kothari1, Julie Stebbins1*, Jessica Leitch2, Amy Zavatsky2
1
Nuffield Orthopaedic Centre, Oxford, OX3 7LD, UK;
2
Department of Engineering Science, University of Oxford, Oxford OX1
3PJ, UK
Table 1(abstract O40) Reliability for identifying
landmarks
95% confidence interval
Intra-observer (n=3)
0.19 mm - 0.37 mm
Inter-observer (n=3)
0.21 mm - 0.57 mm
Background: The use of multi-segment foot models is becoming
increasingly popular during clinical gait analysis. While numerous studies
have established the repeatability of these models, the accuracy is more
difficult to determine since measuring motion of the bones is a
challenging task. One assumption influencing model accuracy is that
surface markers can be placed precisely over palpated, bony landmarks.
The aim of this study is to test this assumption by assessing marker
placement using CT scans.
Materials and methods: Twenty female subjects (forty feet) participated
in this study. All subjects had ECG electrodes attached to their lower limbs
according to the positions required by the Oxford Foot Model [1].
Positioning was performed by a single tester on all subjects. Subjects lay
supine in the CT scanner, in a semi-weight-bearing position using a
custom-built rig. The anatomical landmarks and the positions of the
markers were identified on the scans using a pre-defined protocol. Intraand inter-rater reliability were assessed. Marker placement accuracy was
determined by assessing relevant components of the distance between
markers and bony landmarks.
Results: Good intra- and inter-rater reliability was demonstrated for
identifying markers on the CT images (Table 1). The average distance
between bony landmarks and marker positions differed according to
position on the foot (Figure 1). The mean error was lowest for the base of
5th metatarsal marker (1.2 mm) and highest for the base of 1st metatarsal
(12.7 mm). There was a systematic offset for this marker, due to slight
differences in definition for placing the marker on the skin, and identifying
the bony landmark on CT images. Of the nine marker positions analysed,
seven markers had a mean error of less than 5 mm.
Conclusions: Surface markers can be placed accurately over bony
landmarks on the foot; however, some positions can be more precisely
palpated than others. This should be taken into account when
interpreting results from multi-segment foot models.
Reference
1. Stebbins J, Harrington M, Thompson N, Zavatsky AB, Theologis T:
Figure 1(abstract O40) Mean error (mm) across all feet for all markers.
Page 28 of 56
O41
Correlated joint rotations in the medial foot and the definition of
plantarflexion-dorsiflexion
Thomas M Greiner
Department of Health Professions, University of Wisconsin-La Crosse, La
Crosse, WI 54601, USA
Background: Every foot muscle crosses and acts upon multiple joints.
The close association of foot bones and their supportive ligaments
creates several closed kinematic chains. The movement of one bone
necessitates the movement of several others. Terms that describe foot
motion do not seem to account for these correlated motions. This
presentation shows that “plantarflexion-dorsiflexion” necessitates, and
therefore implies, more than just a rotation at the talocrural joint.
Materials and methods: Observations are drawn from 10 cadaveric
specimens. A rigid cluster was inserted into the tibia, talus, calcaneus,
navicular, medial cuneiform and first metatarsal. An active marker camera
system recorded cluster motion during manual movement of the leg
through several cycles of moving the leg forward and back through the
ankle joint rotation. Functional Alignment [1] processing of the data
determined rotational patterns, and axis orientations, associated with the
subtalar, talonavicular, medial cuneonavicular and first cuneometatarsal
joints. Motion patterns about of these joints were examined as a function
of talocrural plantarflexion-dorsiflexion.
Results: Revealed joint rotations (Figure 1) shows how medial intrinsic
foot joints respond to talocrural plantarflexion-dorsiflexion. Orientation of
the joint axes (Figure 2) shows that the more proximal joints rotate about
anterior-posterior orientated axis, while the axes of the distal joints return
to the roughly medial-lateral axis orientation of the driving action.
Conclusions: The joint motions presented here could be described as
plantarflexion-dorsiflexion rotations, inasmuch as that term describes the
results of the driving action. However, plantarflexion-dorsiflexion typically
describes rotations about a medial-lateral axis [2]. Therefore, the term does
not apply to all the observed rotations. In the experimental setting we can
isolate joint motions and describe them with specific terms. However, in a
normal functioning human no foot joint moves in isolation. Until this
contradiction can be resolved, we currently have no unambiguous definition
of foot plantarflexion-dorsiflexion.
Acknowledgements: Thanks to Dr. Kevin A. Ball, University of Hartford,
for assistance during data collection and initial data processing.
Figure 1(abstract O41) Rotational motion patterns of the medial foot joints responding to talocrural plantarflexion-dorsiflexion.
Figure 2(abstract O41) Orientation of the rotational axes when projected onto a horizontal plane.
Page 29 of 56
References
1. Ball KA, Greiner TM: A procedure to refine joint kinematic assessments:
Functional Alignment. Comput Methods Biomech Biomed Engin 2011, 1:1.
2. Stedman’s Medical Dictionary. Philadelphia: Lippincott, Williams & Wilkins,
28 2006.
O42
Inertial control: a novel technique for in-vitro analysis of foot function
Tassos Natsakis1*, Koen Peeters1, Fien Burg1, Greta Dereymaeker1,
Jos Vander Sloten1, Ilse Jonkers2
1
Mechanical Engineering Department, KU Leuven, Leuven, 3000, Belgium;
2
Department of Kinesiology, KU Leuven, Leuven, 3000, Belgium
Background: In-vitro gait simulations have great potential, allowing a
systematic analysis of the foot function. However, it is important that the
loading conditions are realistic i.e. physiologic ground reaction forces
(GRF). In most experiments, in-vivo measured GRF can be imposed [1,2].
However in experimental designs that evaluate the effect of altered
muscle forces on foot motion this is more complex; the effect of the
altered muscle activity on the loading and kinematics cannot be taken
into consideration. Therefore, we investigated the use of a new technique
to simulate such cases with realistic loading conditions.
Methods: Our gait simulator simulates the activation of nine muscles
(grouped in six groups), based on electromyography measurements. The
forces are applied with pneumatic actuators and are measured by loadcells located between the tendons and the actuators. The set-up is able
to simulate knee motion, using a motor for the horizontal and a platform
under the foot for the vertical direction. The stance phase is simulated in
0.8 seconds.
The GRF in human gait is the sum of a static (human weight) and a
dynamic part (acceleration of human mass). By applying a constant force
on the platform (equal to the assumed weight of the subject), the
measured GRF is the sum of the constant force and the force generated
from the acceleration of the platform. This way, the kinetics are governed
exclusively by the muscle activation.
Results: Four freshly frozen cadaveric specimens were used, for five
measurements each. The in-vitro measured GRF was compared to in-vivo
Figure 1(abstract O42) Comparison of the in-vivo and in-vitro measured GRF.
Page 30 of 56
measurements (figure 1) and followed the normal pattern with an RMS
error of 22%.
Conclusions: Using this method, physiological GRF were reconstructed
for normal gait, by reconstructing the mechanism that generates GRF. It
could be, therefore, used for pathologic gait simulations, since the
mechanism is identical.
Acknowledgments: This work was funded by the Chair BerghmansDereymaeker.
References
1. Sharkey NA, Hamel AJ: A dynamic cadaver model of the stance phase of
gait: performance characteristics and kinetic validation. Clin Biomech
(Bristol, Avon) 1998, 13:420-433.
2. Whittaker E, Aubin P, Ledoux W: Foot bone kinematics as measured in a
cadaveric robotic gait simulator. Gait Posture 2011, 33:645-650.
O43
The development of a kinematic model to quantify in-shoe foot motion
Chris Bishop1*, Gunther Paul2, Dominic Thewlis1,3
1
School of Health Sciences, University of South Australia, Adelaide, South
Australia, 5000, Australia; 2Mawson Institute, University of South Australia,
Adelaide, South Australia, 5041, Australia; 3Sansom Institute for Health
Research, University of South Australia, Adelaide, South Australia, 5000,
Australia
Study aim: To develop a kinematic model to quantify in-shoe foot
kinematics during gait.
Methods and material: Twenty-four participants (mean age - 21.8 yrs ±
3.5 yrs, height - 1.75 m ± 0.09 m and body mass - 71.0 kg ± 10.6 kg)
were recruited. A marker set consisting of 20 x 10 mm markers was
developed to track in-shoe joint kinematics [1]. Reliability and accuracy
estimates of calibration marker placement on the shoe were determined.
To track in-shoe foot motion, 12 mm diameter holes were punched in
the shoe upper, with 25 mm marker wands mounted on the skin through
the shoe (Figure 1). The marker set defined a four-segment kinematic
model of the foot and ankle (shank, hindfoot, midfoot-forefoot complex
and hallux). To define model parameters and moments of inertia, a CT
scan was taken of 12 participant’s feet. The reconstruction of 3-D bone
Page 31 of 56
Figure 1(abstract O43) Shod and in-shoe marker set.
geometries from two-dimensional grey scale images (DICOM format) was
conducted in Simpleware software. Shoe-mounted marker offsets and
moments of inertia were inputted to Visual3D. The kinematics of the shoe
were described before and after modification to quantify post-modification
shoe integrity. The model was deemed sensitive if it detected changes in
joint kinematics between conditions that were both statistically significant
and greater than the calculated Standard Error of Measurement (SEM) [2].
Results: The intra-rater (ICC = 0.68 – 0.99) and inter-rater reliability (ICC =
0.75 – 0.98) of marker placement on the shoe ranged from moderate to
excellent. The error of calibration marker placement on the shoe was < 5
mm compared to skin-mounted markers.
Conclusion: In conclusion, we present an accurate and reliable kinematic
model to describe in-shoe foot kinematics during gait.
Acknowledgements: ASICS Oceania provided the shoes for the study.
Simpleware provided a complimentary software licence used to define
model parameters.
References
1. Bishop C, et al: The development of a multi-segment kinematic model of
footwear. Footwear Sci 2011, 3:S13-S15.
2. Portney LG, Watkins MP: Foundations of Clinical Research: Applications to
Practice. Upper Saddle River, NJ: Pearson/Prentice Hall 2009, xix:892.
was used to investigate the effect of the foot progression angle on the
development of ERLLP.
Results: Forty-six subjects developed ERLLP and 29 of them developed
bilateral symptoms thus giving 75 symptomatic lower legs. Bilateral lower
legs of 167 subjects who developed no injuries in the lower extremities
served as controls. Pearson correlation showed no significant correlation
between the foot progression angle and the eversion excursion (R=.121)
and the medio-lateral pressure distribution (R=.116). Cox regression
analysis showed no significant differences for the foot progression angle
between the injured and uninjured subjects.
Conclusions: The findings of this study suggest that the foot progression
angle is not a risk factor for ERLLP as the foot progression angle is not
related to the amount of eversion and the medio-lateral pressure
distribution.
References
1. Willems TM, De Clercq D, Delbaere K, et al: A prospective study to gait
related risk factors for exercise-related lower leg pain. Gait Posture 2006,
23:91-98.
2. Willems TM, Witvrouw E, De Cock A, et al: Gait-related risk factors for
exercise-related lower-leg pain during shod running. Med Sci Sports Exerc
2007, 39:330-339.
O44
Relationship between the foot progression angle and eversion and
exercise-related lower leg pain
Tine M Willems1*, Erik Witvrouw1, Dirk De Clercq2, Philip Roosen1
1
Department of Rehabilitation Sciences and Physiotherapy, Ghent University,
Ghent, 9000, Belgium; 2Department of Movement and Sport Sciences, Ghent
University, Ghent, 9000, Belgium
O45
Implications of subtalar joint motion for muscle and joint loading
during running
Uwe G Kersting
Center for Sensory-Motor Interaction, Department of Health Science and
Technology, Aalborg University, 9220 Aalborg, Denmark
Background: In clinical practice, out-toeing is often linked with an
increased eversion and an increased medial pressure distribution.
However, in the literature, there is little evidence for this relationship. On
the other hand, as an increased eversion and an increased medial pressure
distribution have been detected as risk factors for exercise-related lower
leg pain (ERLLP) [1,2], and if the foot progression angle is related to these
parameters, the occurrence of ERLLP could be due to an increased foot
progression angle. The purpose of this study was therefore 1) to
investigate the relationship between the foot progression angle and the
amount of eversion and the medio-lateral pressure distribution and 2) to
check if the foot progression angle is a risk factor for ERLLP.
Materials and methods: 3D gait kinematics combined with plantar
pressure profiles were collected from 400 healthy physical education
students. After this evaluation, all sports injuries were registered by a
sports physician during 3 years. Relationship between foot progression
angle and the amount of eversion and the medio-lateral pressure
distribution were tested with Pearson correlation. Cox regression analysis
Background: Rearfoot pronation is one of the factors having been linked
to overuse injuries in running (1). Many studies have used shoe eversion
as a measure for movement about the subtalar joint axis. Others used
foot movement expressed as rotations about the anatomical main axes
(2). If joint coupling and with that muscle loading is to be investigated it
may be beneficial to assess rotations about the anatomical axes, namely
the talocrural and subtalar joints.
The aim of this study was to describe how the relationship of the two
ankle joint movements is affected by moderate geometric changes of the
midsole of a running shoe. Secondly, the relationship of total ankle
movement in main anatomical planes and the two anatomical ankle
joints was to be explored.
Materials and methods: Eleven experienced runners were asked to run
in a running shoe (Nike Pegasus) with neutral (NE), +4° varus (VR) and –4°
valgus (VG) midsole. Subjects were given 1 – 2 km of running to
accommodate. Three-dimensional kinematics were recorded using an
eight-camera system (Motion Analysis Corp., Eva, 120 Hz). Ground reaction
forces were sampled at 1200 Hz from 2 force plates (Bertec).
A lower extremity model was scaled to each individual and inverse
dynamics analysis carried out in the Any Body Modelling System (3).
Subtalar and talocrural joint kinematics, joint kinetics and muscle
activations were extracted after optimisation. Additionally, foot rotations
with respect to the leg segment in the cardinal anatomical planes were
extracted for comparison. Regression techniques were employed to test
for relationships of kinematics and muscle activations (p<.05).
Results: Sagittal plane ankle movement consistently showed significant
correlations with talocrural joint excursions while movement about the
subtalar joint showed moderate to high correlations to movement in
the frontal and transverse planes. However, for some subjects these
relationships were inverted for non-neutral shoe conditions. Muscle forces
were generally closer related to rotations about the anatomical joint axes
than projected to the cardinal planes.
Conclusions: When addressing the relationship between soft tissue
loading and joint kinematics anatomical joint axes orientations should be
preferred. It remains, however, open to verification how such loading
distribution is affected by anatomical variations in individuals.
References
1. Nigg BM: The role of impact forces and foot pronation: a new paradigm.
Clin J Sport Med 2001, 11:2-9.
2. Ferber R, Davis IM, Williams DS 3rd: Gender differences in lower extremity
mechanics during running. Clin Biomech (Bristol, Avon) 2003, 18:350-357.
3. Andersen MS, Damsgaard M, MacWilliams B, Rasmussen J: A computationally
efficient optimisation-based method for parameter identification of
kinematically determinate and over-determinate biomechanical systems.
Comput Methods Biomech Biomed Engin 2010, 13:171-178.
O46
Do lower extremity kinematics and training variables affect the
development of overuse injuries in runners? - a prospective study
Tobias Hein*, Pia Janssen, Ursula Wagner-Fritz, Stefan Grau
Department of Sports Medicine, Medical Clinic, University of Tübingen,
Tübingen, Germany
Background: The incidence of running injuries appears to be multi-factorial,
e.g. with regard to training errors or kinematics of the lower extremity [1,2].
To date, studies examining differences between healthy and injured runners
are mainly retrospective, and therefore not able to determine whether these
differences are the cause or effect of injury. The goal of this prospective
study is to evaluate whether the development of overuse injuries in initially
healthy subjects is caused by alterations in lower extremity kinematics and/
or training habits.
Materials and methods: Since April 2009, 218 healthy runners (m=139,
w=79) have been included in the study. Besides a standardized clinical
examination, 3D-kinematics of both lower extremities were recorded
according to ISB-recommendations [3]. Hip, knee and ankle joint motions
were quantified by calculating Cardan angles [4]. Mean angular
displacements and discrete parameters were calculated from 10 valid trials
of barefoot running. All subjects were asked to complete and return
weekly training logs with information about their weekly mileage, running
time, and type of training sessions, as well as information about the
occurrence of pain during training. Study duration lasted a maximum of
12 months or until diagnosis of an overuse injury.
Results: Currently, 35 from 104 subjects who have completed the study
have developed overuse injuries. Symptomatic runners ran more training
kilometers per week than healthy runners, and showed a shift from slow
and medium to fast endurance training sessions. Further, runners who
generated overuse injuries exhibited differences in rear foot, ankle and
knee kinematics compared to runners who remained uninjured during
their participation.
Conclusions: The initial results indicate that lower leg kinematics and
training parameters are risk factors and consequently possible causes for
developing overuse injuries. Further subjects will be included in the
evaluation to enable a division into larger injury-specific groups.
References
1. van Gent RN, Siem D, van Middelkoop M, et al: Incidence and
determinants of lower extremity running injuries in long distance
runners: a systematic review. Br J Sports Med 2007, 41:469-480.
Page 32 of 56
2.
3.
4.
Willems TM, De CD, Delbaere K, Vanderstraeten G, et al: A prospective
study of gait related risk factors for exercise-related lower leg pain. Gait
Posture 2006, 23:91-98.
Wu G, Siegler S, Allard P, et al: ISB recommendation on definitions of joint
coordinate system of various joints for the reporting of human joint
motion–part I: ankle, hip, and spine. International Society of
Biomechanics. J Biomech 2002, 35:543-548.
Grood ES, Suntay WJ: A joint coordinate system for the clinical
description of three-dimensional motions: application to the knee.
J Biomech Eng 1983, 105:136-144.
O47
Abstract withdrawn
Abstract withdrawn:
O48
Effects of weight loss on foot structure in obese adults: a pilot study
Jinsup Song1*, Gary Foster2, Reagan Kane1, Dana N Tango1,
Stephanie Vander Veur2, Naomi Reyes2, Caitlin LaGrotte2, James Furmato1,
Eugene Komaroff2
1
Gait Study Center, Temple University, Philadelphia, PA, USA; 2Center for
Obesity Research and Education, Temple University, Philadelphia, PA, USA
Background: Excessive body weight can have a profound influence on
weight bearing structure and function, including pain, disability, and
compromised quality of life. A prospective cohort study of 5,784 people
over the age of 50 years, showed that obesity was a strong predictor of
the onset of severe disabling knee pain.[1] Similarly, increased weight
was found to have an association with chronic plantar heel pain
syndrome.[2] No study to-date has conducted an objective prospective
examination of the differences in foot structure and function during
significant weight change.
Materials and methods: In this randomized controlled prospective pilot
study, 41 obese subjects were randomly assigned to either the treatment
or the control group. Subjects assigned to the treatment group received
weekly education plus pre-packaged portion-controlled meals while the
control group received monthly education only. Foot structure
measurements (malleolar valgus index and arch height) were assessed at
baseline and 3-month. Repeated ANOVA (Matched Pairs by Group)
analysis was performance using JMP 9.
Results: The mean age of study participants was 56.2 years old. While there
was no difference in body mass index between the two groups at baseline,
the treatment group lost significant weight at 3-month, see Table 1.
Conclusions: No significant changes were noted in measured structural
foot parameters at 3-month follow up between the two groups as a
Table 1(abstract O48) Summary of foot structure
measures of the control and the treatment groups at
baseline and 3-month
Control
Treatment
p-value
Baseline 3-month Baseline 3-month
a
35.8
35.1
36.1
34.0
<0.0001
Malleolar Valgus
Index (%)
12.9
12.9
13.4
12.7
0.3103
Standing arch
height (cm)
6.11
6.18
5.99
6.02
0.5593
Arch drop (cm)
0.44
0.40
0.43
0.47
0.0828
Body Mass Index
a
Control group lost an average of 1.9 kg (2.9%) of body weight while the
treatment group lost 5.9 kg (6.2%) at 3-month visit.
Page 33 of 56
Figure 1(abstract O48) Linear correlation of (a) body weight and standing arch height at baseline [StdArchHt = 4.036 + 0.020 * Weight, p<0.0001],
(b) body weight and arch drop at baseline [Arch drop= 0.075 + 0.003 * weight, P=0.006], and (c) change in weight and change in standing arch height
[ΔStdArchHt = -.0114 + 0.016 * Δ Weight, P=0.013].
function of observed weight loss. It is not clear if a larger weight reduction
would have yielded significant changes. Several foot dimensions (including
standing arch height and arch height drop from the sitting to standing
conditions) were linearly correlated with body weight.
Acknowledgements: Nutrisystem, Inc. provided the pre-packaged
portion-controlled meals for the study.
References
1. Jinks C, et al: Disabling knee pain – another consequence of obesity:
Results from a prospective cohort study. BMC Public Health 2006, 6:258.
2. Irving DB: Obesity and pronated foot type may increase the risk of
chronic plantar heel pain: a matched case-control study. BMC
Musculoskelet Disord 2007, 8:41.
O49
Effects of extrinsic foot musculature on hindfoot kinematics during
stance phase: Implications for flatfoot pathology
Josefien Burg1,2*, Koen Peeters1, Tassos Natsakis1, Jos Vander Sloten1,
Greta Dereymaeker1, Ilse Jonkers2
1
Mechanical Engineering Department, K.U.Leuven, Belgium; 2Department of
Kinesiology, K.U.Leuven, Belgium
Background: Flatfoot deformity is a common condition, characterized by
a collapse of the medial foot arch. Specific muscle dysfunctions relate to
kinematic changes of the hind foot (plantarflexion, abduction and valgus)
inducing the onset of flatfoot deformity. However, to determine a causal
relation between individual muscle action, foot bone motion and flatfoot,
in vitro experiments are needed. Our hypothesis states that inducing
altered muscle forces in cadaveric feet causes alterations in kinematics,
representative for flatfoot deformity [1,2].
Materials and methods: A gait simulator was used to test seven
cadaveric feet. Pneumatic actuators applied forces to the foot tendons,
simulating flatfoot related pathologies: contracture of M.Triceps Surae
(C-TS) and Mm.Peronei (C-PE); weakness of M.Tibialis Posterior (W-TP) and
the pretibial muscles (W-PT); combined contracture of TS and PE (P1) and
combined TS contracture with TP weakness (P2). Trajectories of boneembedded LED clusters were measured during a one second roll-off and
resulting ankle, subtalar and talonavicular joint motion was calculated.
Results: At all joint levels, increased motion towards valgus and
adduction is seen. Exceptions are subtalar abduction with C-PE and C-TS
as well as ankle and subtalar varus for C-PE and P1. More variability is
observed for plantar-dorsiflexion: all joints show plantarflexion with C-TS
and W-PT, except for subtalar dorsiflexion with W-PT. Dorsiflexion appears
with W-TP and C-PE.
Conclusion: We can confirm the contribution of altered muscle action
(either contracture or weakness) to flatfoot development. Our results
suggest that largest contribution is present in frontal and sagittal plane,
with hindfoot motion towards valgus and plantarflexion. No abduction
was seen, suggesting lesser contribution of these pathologies in the
transverse plane. This study contributes to fundamental knowledge on
Figure 1(abstract O49) Kinematic changes at the ankle joint with three levels of TSC.
foot biomechanics in normal as well as pathological foot function and
establishes the causal relation between modified muscle action and
flatfoot deformity.
Acknowledgements: This work was funded by the Chair BerghmansDereymaeker and the Agency for Innovation by Science and Technology,
Flanders.
References
1. Wülker N, Hurschler C, Emmerich J: In vitro simulation of stance phase
gait part II: simulated anterior tibial tendon dysfunction and potential
compensation. Foot Ankle Int 2003, 24:623-629.
2. Ness MA, Long J, Marks R, Harris G: Foot and ankle kinematics in patients
with posterior tibial tendon dysfunction. Gait Posture 2008, 27:331-339.
O50
Influence of variable stiffness shoes in sports performance and
protection of lower extremity injury
Jee-Chin Teoh*, Wen-Min Chen, Taeyong Lee
Division of Bioengineering, National University of Singapore, Singapore
Background: Footwear is an effective biomechanical solution to lower
extremity joint problems. Variable stiffness shoe (VSS) is designed. It has
been proved to reduce knee internal abduction (external adduction)
moment [1]. This helps to slow down progression of medial knee
osteoarthritis (OA) [2]. However, there is no study on the effects of VSS
Page 34 of 56
on lower extremity during dynamic activities besides walking. Influence of
VSS in sports performance is also yet to be examined. This study aims to
investigate the biomechanical influence of VSS on lower extremity during
dynamic activities and to assess the potential of VSS in improving sports
performance.
Materials and methods: 15 female and 15 male subjects walked in 2
conditions: VSS and Control. VSS had a lateral sole 1.6 times stiffer than
medial (Figure 1). The optimized ratio was obtained from finite element
analysis of a simplified 2D knee model. Control had uniform stiffness
outsole.3D kinematic and kinetic analysis was conducted during walking,
running, stop jumping and lateral hopping. Rating on footwear comfort
was also performed.
Results: Increased posterior force during running and stop jumping
(Table 1) ensured controlled gait termination and reduced the risk of fall.
Increased anterior force during walking and running (Table 1) increased
forward propulsion and acceleration. Knee internal abduction moment
was generally reduced (Table 1). This showed potential of VSS as
sportswear that helped to relieve medial knee loading in more vigorous
activities such as running, stopping and jumping. Kinetic data and
comfort data showed that VSS did not change gait kinematics much.
Rating differences were all insignificant (p<0.05). The stiffness variation in
VSS was hardly noticeable. Shoe comfort was not compensated in VSS.
Conclusion: The study demonstrated great potential of VSS in improving
sports achievement and protecting knee. Outsole configuration can be
further modified by varying outsole stiffness along anteroposterior axis
for better performance and protection.
Figure 1(abstract O50) Images of shoe bottom and shoe cross section showing lateral (L) and media (M) soles.
Page 35 of 56
Table 1(abstract O50) Table compares only the averages of kinematics (angles) and kinetics (moments and forces)
data that are statistically significant (p<0.05) during the dynamic activities
Activity
Joint
Variable Name
Control
VSS
%difference
Walking
Knee
Max adduction moment (%BWxHt)
0.37
0.35
-5.994
Max anterior force at push off (%BW)
19.73
20.97
6.302
Knee
Max posterior force (%BW)
1.04
-24.50
0.88
-28.93
-14.716
18.072
Max anterior force (%BW)
29.02
30.78
6.078
0.83
0.67
-18.661
Max posterior force (%BW)
-67.67
-73.33
8.373
Walking
Running
Running
Running
Stop Jumping
Stop Jumping
Knee
References
1. Erhart JC, Mundermann A, Elspas B, et al: A variable-stiffness shoe lowers
the knee adduction moment in subjects with symptoms of medial
compartment knee osteoarthritis. J Biomech 2008, 41:2720-2725.
2. Miyazaki T, Wada M, Kawahara H, et al: Dynamic load at baseline can
predict radiographic disease progression in medial compartment knee
osteoarthritis. Ann Rheum Dis 2002, 61:617-622.
O51
The effect of external ankle support on knee and ankle joint loading in
netball players
Benedicte Vanwanseele1,2,3*, Max Stuelcken2, Andy Greene2, Richard Smith2
1
Health Innovation and Technology Department, Fontys University of
Applied Sciences, Eindhoven, The Netherlands; 2Exercise, Health and
Performance Research Group, The University of Sydney, Australia;
3
Departement of Biomedical Kinesiology, KULeuven, Leuven, Belgium
Background: External ankle support has been successfully used to
prevent ankle sprains [1]. However, some recent studies [2,3] have
indicated that reducing ankle range of motion can place larger loads on
the knee and increase the risk of knee injuries. The aim of this study is to
investigate the effect of external ankle support (braces and high top
shoes) on ankle kinematics and knee kinetics in high performance netball
players.
Materials and methods: Eleven high performance netball players were
recruited from NSW Institute of Sport. A 14-camera motion analysis system
was used to synchronously collect three-dimensional video and force plate
data. Twenty-four retro-reflective markers were attached to anatomical
landmarks to allow the formation of rearfoot, forefoot, shank, thigh, and
pelvis segments. Each player performed a single-leg-landing whilst
receiving a chest pass. There were three conditions: a standard netball
shoe (Ignite 3, ASICS), a standard netball shoe in conjunction with a semirigid ankle brace, and a high top basketball shoe (Jordan, NIKE). Five trials
were analysed for each condition. Comparisons between the brace and the
standard shoe conditions; and between the high top and the standard
shoe conditions were made using the Wilcoxon sign-rank test.
Results: The maximal ankle eversion angle was significantly larger in the
standard shoe condition compared to the brace condition (12.35±8.62 vs
7.79±4.60 degrees, p=0.038) (Figure 1). The same trend was observed
when comparing the standard and high top shoe conditions (8.79±3.87
degrees) but significance was not reached.
None of the moments were significantly different between the conditions
but there was a trend for an increased ankle plantarflexion moment and
hip flexor moment in the brace condition compared to the standard shoes.
Conclusions: Although the ankle eversion angle was restricted by use of
an external brace, no changes in the knee and ankle joint moments were
observed.
Figure 1(abstract O51) Average time series for the ankle angle in the frontal plane during a single-leg-landing wearing standard netball shoes, standard
netball shoes with brace and high top shoes.
References
1. Quinn K, Parker P, de Bie R, Rowe B, Handoll H: Interventions for preventing
ankle ligament injuries. Cochrane Database Syst Rev 2000, 2:CD000018.
2. Venesky K, Docherty CL, Dapena J, Schrader J: Prophylactic ankle braces and
knee varus-valgus and internal-external rotation torque. J Athl Train 2006,
41:239-244.
3. Mündermann A, Nigg BM, Humble RN, Stefanyshyn DJ: Foot orthotics
affect lower extremity kinematics and kinetics during running. Clin
Biomech (Bristol, Avon) 2003, 18:254-262.
O52
Perceived ankle instability is not related to ankle joint position sense,
movement detection and inversion/eversion peak power: an
observational study
Fereshteh Pourkazemi1*, Claire Hiller1, Jacqueline Raymond2, Kathryn Refshauge1
1
School of Physiotherapy, Faculty of Health Scineces, University of Sydney,
NSW, Australia; 2School of Exercise and Sport Sciences, Faculty of Health
Scineces, University of Sydney, NSW, Australia
Background: It is not known why continuing instability exists after
ankle sprain. The most common hypotheses include impairments in
proprioception, muscle power or postural control [1] but a relationship has
not been established. Therefore, the aim of this study was to investigate the
relationship between functional instability and invertor/evertor peak power,
accuracy of movement detection and threshold for position sense in the
ankle.
Materials and methods: Sixty three participants with history of either no
ankle sprain or only one ankle sprain were recruited. Functional ankle
instability was measured using the Cumberland Ankle Instability Tool (CAIT),
a highly reliable measure of functional ankle instability [2]. Invertor/evertor
power testing was performed using a Biodex isokinetic dynamometer at
speeds of 30, 60 and 120°/sec and the scores were normalised using
participants’ BMI. Joint position sense was measured by actively matching
the 3 test angles in inversion and eversion with the contra lateral ankle.
Movement detection sense was tested at three velocities, 0.1, 0.5, and 2.5°/
sec, in a random order. The relationship between perceived ankle instability
and proprioception or inversion/eversion peak power was investigated using
Pearson product-moment correlation coefficient. Preliminary analyses were
performed to ensure the assumptions of normality, linearity and
homoscedasticity were not violated.
Results: No correlation was found between the CAIT scores and the three
measured variables. The strongest correlation was between CAIT score and
inversion peak power at 30°/s (r=0.220, p= 0.083).
Conclusion: Based on our findings, functional ankle instability (as
measured by CAIT) is not related to inversion/eversion peak power, or
with joint movement detection or position sense at the ankle. These
findings are consistent with the results of previous studies investigating
the relationship between CAIT score and other functional tests [3]. The
lack of a relationship suggests that impaired proprioception and muscle
power do not explain perceived ankle instability.
References
1. Hertel J: Functional anatomy, pathomechanics, and pathophysiology of
lateral ankle instability. J Athl Train 2002, 37:364-375.
2. Hiller CE, Refshauge KM, Bundy AC, Herbert RD, Kilbreath SL: The
Cumberland ankle instability tool: a report of validity and reliability
testing. Arch Phys Med Rehabil 2006, 87:1235-1241.
3. De Noronha M, Refshauge KM, Kilbreath SL, Crosbie J: Loss of
proprioception or motor control is not related to functional ankle
instability: an observational study. Aust J Physiother 2007, 53:193-197.
O53
Syndesmosis ankle injury in football players: a pilot study
Amy Sman1*, Claire Hiller1, Leslie Nicholson1, Katherine Rae2,
Kathryn Refshauge1
1
Department of Physiotherapy, University of Sydney, Sydney, NSW, 2137,
Australia; 2The Sports Clinic, University of Sydney, Sydney, NSW, 2006, Australia
Page 36 of 56
Background: Syndesmosis ankle injury, also known as ‘high’ ankle sprain,
appears to be increasingly common [1]. The injury occurs most commonly
in high impact contact sports [2] resulting in greater impairment and
longer rehabilitation than the typical ankle sprain [3,4]. However, no
prospective study has investigated predictors and prognostic factors for
syndesmosis injury.
Materials and methods: We recruited football players from Sydney
University Rugby Union and AFL clubs. The only exclusion criterion was
symptoms at the time of screening that would affect baseline testing
performance. Trained assessors conducted pre-season screening and
participants were then followed for the season. The suite of baseline tests
included vertical jump, star excursion balance test, single leg triple hop for
balance and heel rise test. History of ankle injury and competition level
was also recorded. Players who sustained an ankle injury during the
season were retested within 2 weeks of injury or on removal of the boot,
and when returned to play. Re-testing involved the weight bearing lunge,
vertical jump, star excursion balance and a fear avoidance beliefs
questionnaire.
Results: During the 2011 season 102 players were screened, with 22
sustaining an ankle injury (13 lateral, 7 syndesmosis and 2 medial ankle
sprains confirmed by MRI). Pilot results suggest that vertical jump
performance together with a history of ankle sprain could be predictors for
syndesmosis injury. Lower vertical jump height was highly correlated with
longer recovery (r= -.571, p= .007). On average, recovery from syndesmosis
injury took 85 days and lateral ankle sprains took 21 days. A difference of
13 cm was found between vertical jump following syndesmosis injury
(32cm) and lateral ankle sprains (49cm).
Conclusions: Sports medical staff and clinicians can use the results of
this pilot study for screening and rehabilitation purposes. However,
further study with a larger cohort is required and underway.
References
1. Jones MH, Amendola A: Syndesmosis sprains of the ankle: a systematic
review. Clin Orthop Relat Res 2007, 455:173-175.
2. Gerber JP, Williams GN, Scoville CR, Arciero RA, Taylor DC: Persistent
disability associated with ankle sprains: a prospective examination of an
athletic population. Foot Ankle Int 1998, 19:653-660.
3. Uys HD, Rijke AM: Clinical association of acute lateral ankle sprain with
syndesmotic involvement: a stress radiography and magnetic resonance
imaging study. Am J Sports Med 2002, 30:816-822.
4. Williams GN, Jones MH, Amendola A: Syndesmotic ankle sprains in
athletes. Am J Sports Med 2007, 35:1197-1207.
O54
The validity of footprint-based measures of arch structure: revisiting
the debate of fat versus flat feet in adults
Hin-Chung Lau1,2*, Scott C Wearing1,2, Nicole L Grigg3, James E Smeathers3
1
Faculty of Health Sciences and Medicine, Bond University, Queensland,
4229, Australia; 2Centre of Excellence for Applied Sport Science Research,
Queensland Academy of Sport, Queensland, 4111, Australia; 3Institute of
Health and Biomedical Innovation, Queensland University of Technology,
Queensland, 4059, Australia
Background: Previous research employing footprint-based measures of
arch structure, such as the arch index (AI), have indicated that obesity results
in a ‘flatter’ foot type [1]. In the absence of radiographic measures, however,
definitive conclusions regarding the osseous alignment of the foot cannot
be made. This study evaluated the effect of Body Mass Index (BMI) on
radiographic and footprint-based measures of adult arch structure.
Materials and Methods: A convenience sample of 30 healthy adults (10
male and 20 female, mean (±SD) age 47.9 ± 11.6 years, height 1.68 ±
0.1m, body weight 80.8 ± 10.2kg, BMI 28.8 ± 2.9kg.m-2) were recruited.
The calcaneal-first metatarsal angle (CMT1) (Figure 1a) was derived from
weight-bearing lateral radiographs [2], while the AI was calculated from
electronic footprints (EMED-SF, Novel GmbH, Germany) as the ratio of
the area of the midfoot relative to the total foot contact area ignoring
the digits (Figure 1b). Multiple regression models were used to evaluate
the independent influence of BMI, age, and arch structure (as defined by
CMT1 angle) on the footprint-based AI, and investigate whether BMI, age,
and AI were significant predictors of CMT1 angle.
Page 37 of 56
Figure 1(abstract O54) Illustration of radiographic (a), and footprint-based measures of arch structure (b).
Results: Both BMI (b=0.39, P=0.04) and CMT1 angle (b=0.51, P<0.01) were
significant predictors of footprint-based measures of arch structure (AI).
The CMT1 angle accounted for 30% of the variability in AI, while BMI
accounted for 15% of the variation in AI. In contrast, CMT1 angle was not
significantly associated with BMI (b=-0.03, P=0.89) when AI and age were
held constant. Age was not a significant predictor of either index.
Conclusions: Adult obesity does not influence the osseous alignment of
the medial longitudinal arch, but selectively distorts footprint-based
measures of arch structure. Consequently, footprint-based measures
should be interpreted with caution when comparing groups of adults
with varying body composition.
Acknowledgements: Mr Lau is funded through an Australian Research
Council Linkage Grant and a Queensland Academy of Sport Fellowship.
Dr Wearing is funded through a Smart Futures Fellowship, Department of
Employment, Economic Development and Innovation, Queensland
Government.
References
1. Gravante G, Russo G, Pomara F, et al: Comparison of ground reaction
forces between obese and control young adults during quiet standing
on a baropodometric platform. Clin Biomech 2003, 18:780-782.
2. Wearing S, Smeathers J, Yates B, et al: Sagittal movement of the medial
longitudinal arch is unchanged in plantar fasciitis. Med Sci Sports Exerc
2004, 36:1761-174.
POSTER PRESENTATIONS
P1
Feasibility and utility of a multi-segment foot model to measure joint
kinematics in older aged adults during gait
John Arnold*, Shylie Mackintosh, Sara Jones, Dominic Thewlis
Australia, 5000, Australia
Journal of Foot and Ankle Research 2012, 5(Suppl 1):P1
Background: Multi-segment foot models (MSFMs) have been developed
for the representation of foot kinematics [1,2]. Despite the existence of
models for different populations there is a paucity of information about
the feasibility and utility of these models in older aged individuals. As
both morphological and functional differences of the feet exist between
different age groups, it is important to establish if it is feasible to apply
the models developed for younger age groups in older individuals.
Materials and methods: Participants were individuals aged 50 to 90 years
who could ambulate independently and were free of any known
neurological or musculoskeletal disorders. A five segment foot and ankle
model was selected for use in this study [3]. Five walking trials were
collected from each participant. Kinematic and ground reaction force data
were collected with twelve optoelectronic cameras (FLEX:V100R2,
OptiTrack, Natural Point Inc., Oregon, USA) and two force platforms (Kistler
Instrument Corp, Switzerland) at 100 Hz and 400 Hz respectively. Data
were exported to Visual3D v4.0 for analysis (C-Motion Inc., MD, USA).
Marker placement reliability (intra and inter-rater) was assessed by two
raters applying markers on two occasions. The propagation of differences
in marker placement to stance phase joint kinematics was explored,
including evaluation of model repeatability.
Results and conclusions: Data collection for the study will be finalised
in January 2012. Statistical analysis of the data will be performed with the
findings prepared for presentation. It is anticipated that the results of this
study will provide preliminary evidence to justify the selection of this foot
model for use in older aged individuals.
References
1. Rankine L, et al: Multisegmental foot modelling: a review. Crit Rev Bio Eng
2008, 36:127-181.
2. Deschamps K, et al: Body of evidence supporting the clinical use of 3D
multisegment foot models: a systematic review. Gait Posture 2011,
33:338-349.
3. Leardini , et al: Rear-foot, mid-foot and fore-foot motion during the
stance phase of gait. Gait Posture 2007, 25:453-462.
P2
Systematic review on the use of foot orthosis in symptomatic pes
planus
Helen A Banwell*, Shylie Mackintosh, Dominic Thewlis
Australia, 5001, Australia
Background:
Physiologic (flexible) pes planus (flatfoot) is a descriptive term for feet that
have a visually lowered medial longitudinal arch often in association with
rearfoot eversion [1]. Reported to affect approximately 15% of the adult
population [2] physiologic pes planus can be categorised as either
symptomatic (painful, non-functional) or non-symptomatic (non-painful,
functional) with the literature purporting that flexible non-symptomatic
pes planus is a predominantly benign condition with no justification for
intervention [3]. When pes planus is symptomatic however, functional foot
orthoses are often prescribed and are the most commonly quoted
intervention within the literature[4]. Despite some controversy for their use
in pes planus, functional foot orthoses remain the cornerstone of podiatric
management of this common disorder. The aim of this review is to
evaluate the evidence for the use of foot orthoses in adults with
symptomatic pes planus.
Materials and methods: A systematic review of randomised, quasirandomised or controlled clinical trials comparing rigid or semi-rigid
functional foot orthoses with: no orthoses or any other approach to
managing symptomatic flexible pes planus in the adult. Relevant data
bases were searched from inception to October 2011 with studies meeting
the predetermined inclusion criteria retrieved and screened by two
independent reviewers. No restrictions were placed on type of foot
orthoses or alternative interventions. Included studies were independently
assessed by two reviewers with risk of bias determined by the Cochrane
criteria. Where feasible, meta-analysis will be undertaken.
Results: A narrative summary will be presented of the results with
outcome measures to include: pain, gait changes (efficiency, temporal
or spatial changes), dynamic foot function or static foot posture
changes.
Conclusion: A determination of the current level/s of evidence for the
use of foot orthoses in the adult with symptomatic pes planus.
References
1. Otman S, Basgoze O, Gokce-Kutsal Y: Energy cost of walking with flat feet.
Prosthet Orthot Int 1988, 12:73-76.
2. Kosashvili Y, et al: The correlation between pes planus and anterior knee
or intermittent low back pain. Foot Ankle Int 2008, 29:910-913.
3. Staheli LT: Planovalgus foot deformity - Current status. J Am Podiat Med
Assn 1999, 89:94-99.
4.
Esterman A, Pilotto L: Foot shape and its effect on functioning in Royal
Australian Air Force recruits. Part 2: pilot, randomized, controlled trial of
orthotics in recruits with flat feet. Mil Med 2005, 170:629-633.
P3
Using standard treatment and offloading principles to heal a wound of
a patient who ambulates upon “all fours”
Lindy Begg1*, Patrick McLaughlin2,3, Karin Sutton4, Thomas Daly1,
Mauro Vicaretti1, Joshua Burns1,5
1
Foot Wound Clinic, Department of Surgery, Westmead Hospital, NSW, 2145,
Australia; 2School of Biomedical and Health Sciences, Faculty of Health,
Engineering and Science, Victoria University, Melbourne 8001, Australia;
3
Institute of Sport, Exercise and Active Living, Victoria University, Melbourne,
8001, Australia; 4The Podiatry Clinic, 51 Station Street, Wentworthville, NSW,
2145, Australia; 5Institute for Neuroscience and Muscle Research, The
Children’s Hospital at Westmead/Paediatric Gait Analysis Service of New
South Wales/Faculty of Health Sciences, The University of Sydney, NSW,
2145, Australia
Background: A 71 year old, weighing 80 kg was referred to the Foot
Wound Clinic despite not having feet. The patient had suffered a
traumatic Above Knee Amputation of the right limb and an Above Knee
Amputation of the left limb from the same incident in 1969. The patient
ambulates on “all fours” or upon the femurs alone and continues to work
full-time as a landscaper. The patient presented for review of a wound
over the right stump with the expectation that he would undergo
surgical debridement and a skin graft. The patient had adequate arterial
flow therefore with standard wound care and offloading, healing should
ensure. The patient has been referred to Rehabilitation Services for
review and in the interim consented to being treated with a Total
Contact Cast (TCC).
Materials and methods: Pressure to the stumps was assessed using
emed® (novel Gmbh, Germany). A total contact cast incorporating 6 mm
slow-rebound cellular urethane and 6 mm soft cellular urethane inlay as
described previously [1] was fabricated for the right stump. The TCC was
removed and a capacitance sensor insole (pedar®, novel Gmbh, Germany)
was placed within the cast measuring medially to laterally including the
wound site.
Results: The area of maximum pressure was 54 cm2 and peak pressure
was 425 kPa at the stump of the right femur using the emed®; average
maximum pressure indicated that pressure was born at the medial to
lateral area of the stump with less than 15 kPa recorded at the wound
site using the pedar®. The VAS score of 7 was reported prior to the TCC
and 0 following the intervention. The patient reported an increase in
activity levels.
Conclusions: Healing is imminent due to the femur being held in
suspension within the TCC. This case history highlights that a challenging
patient notwithstanding; standard assessment and intervention is
essential.
Reference
1. Burns J, Begg L: Optimizing the offloading properties of the total contact
cast for plantar foot ulceration. Diabetic Med 2011, 28:179-185.
Page 38 of 56
this review was to investigate the relationship between foot type and
dynamic lower limb and foot kinematics during walking.
Materials and methods: A systematic database search of MEDLINE,
CINAHL, SPORTDiscus, Embase and Inspec was undertaken in May 2011.
Two independent reviewers applied predetermined inclusion criteria to
select articles for review. A two stage quality assessment was also
undertaken for selected articles. Firstly, methodological quality was
assessed using a modified version of the Quality Index. Secondly,
kinematic methodology and reporting were assessed using a series of
items derived from relevant references.
Results: A final selection of 14 articles was reviewed from an initial list of
3470 citations. Meta-analysis was not conducted due to heterogeneity
between studies. Quality Index scores ranged from 44-94% (mean 74%)
and kinematic methodology, while varied, was generally repeatable.
Selected articles mainly focused on low-arched and normal foot types.
Articles could be grouped into two broad categories. Firstly, studies that
compared mean differences found some evidence for increased motion
in low-arched feet, but this was limited by small effect sizes. Secondly,
studies that investigated associations found that a more pronated foot
type was correlated with increased peak rearfoot eversion and total
rearfoot eversion range of motion during walking.
Conclusions: There is some evidence for a relationship between lowarched feet and increased motion during gait, however this was not
conclusive due to heterogeneity between studies and small effect sizes.
Future research should focus on a broader range of foot types including
high-arched feet.
P5
Effect of functional fatigue on vertical ground reaction force among
individuals with flat feet
Sahar Boozari1, Ali Ashraf Jamshidi1,2*, Mohammad Ali Sanjari2, Hassan Jafari1
1
Department of Physical Therapy, Tehran University of Medical Sciences,
Tehran, 1545913187, Iran; 2Biomechanics Laboratory, Rehabilitation Research
Center, Tehran University of Medical Sciences, Tehran, 1545913187, Iran
Background: Flat foot as one of the lower extremity deformities might
change some kinetic variables of gait. Fatigue can deteriorate the muscle
ability in supporting joints and can alter the vertical ground reaction
force (GRF) [1,2]. This study examined the fatigue effect on vertical GRF in
individuals with flat feet compared with a normal group during barefoot
walking.
Materials and methods: Seventeen subjects with flat feet and 17 normal
subjects completed the test. Three vertical GRF measures (F1 ; the first
peak force, F 2 ; minimum force; and F 3 ; the second peak force) were
P4
The relationship between foot type and lower limb kinematics during
walking: a systematic review
Andrew K Buldt1,2*, George S Murley1,2, Paul Butterworth1,2, Pazit Levinger2,
Hylton B Menz2, Karl B Landorf1,2
1
Bundoora 3086, VIC, Australia; 2Musculoskeletal Research Centre, Faculty of
Health Sciences, La Trobe University, Bundoora 3086, VIC, Australia
Background: Variations of foot type, such as a low- or high-arched foot,
are thought to be an intrinsic risk factor for lower extremity injury. One
of the proposed mechanisms by which foot posture may contribute to
injury is via altered motion of the lower extremity. Therefore, the aim of
Figure 1(abstract P5) Vertical GRF curves for a subject with flat feet
and a subject with normal feet after fatigue.
extracted before and after a functional fatigue protocol. To check the
homogeneity of the velocity among conditions, the average velocity of
the anteroposterior center of pressure (COPy) excursion was calculated.
A repeated measure ANOVA was conducted to analyze data.
Results: For the average COPy velocity, no significant fatigue, group and
interaction effects were seen. F 2 was higher in the flat feet group
compared with the normal group (p < 0.05). The fatigue protocol resulted
in higher F2 and lower F3 in both groups (p < 0.05). See Figure 1. as the
sample vertical GRF curves for a subject with flat feet and a subject with
normal feet after fatigue.
Conclusions: The higher F 2 in the flat feet group, which results in a
decrease drop in vertical GRF, might be due to more flexible foot joints.
Foot muscles lose their appropriate ability to control the foot joints and
MLA due to fatigue [2-4] which results in higher F 2 for both groups.
Furthermore the muscles could not make a proper lever arm for the
propulsion gait phase after fatigue [2] resulting in lower F3 for both
groups.
Acknowledgement: This study was funded and supported by Tehran
University of Medical Sciences.
References
1. Gerritsen K, Van Den Bogert A, Nigg B: Direct dynamics simulation of the
impact phase in heel-toe running. J Biomech 1995, 28:661-668.
2. Christina K, White S, Gilchrist L: Effect of localized muscle fatigue on
vertical ground reaction forces and ankle joint motion during running.
Hum Mov Sci 2001, 20:257-276.
3. Thordarson D, Schmotzer H, Chon J, Peters J: Dynamic support of the
human longitudinal arch: a biomechanical evaluation. Clin Orthop 1995,
316:165-172.
4. Headlee D, Leonard J, Hart J, Ingersoll C, Hertel J: Fatigue of the plantar
intrinsic foot muscles increases navicular drop. J Electromyogr Kinesiol
2008, 18:420-425.
P6
The effect of a subject-specific AFO on the muscle activation during
gait of a test subject suffering from a hemiparetic anterior muscle
insufficiency in the lower leg
V Creylman1,2*, L Muraru1,2, H Vertommen1,2, L Peeraer1,3
1
Mobilab, University College Kempen, Belgium; 2Division of Biomechanics,
KULeuven, Belgium; 3Faculty of Kinesiology and Rehabilitation Sciences,
KULeuven, Belgium
Background: An Ankle Foot Orthosis (AFO) is commonly used in clinical
practice to assist gait of patients with different pathologies. The flexibility
of the AFO depends on different design characteristics while specific
mechanical requirements of the AFO are correlated with patient anatomy
and pathology. To this day, the correlation between AFO-design and
patient pathology is mainly based on the orthopaedic technician’s
experience.
The aim of this study is to investigate the influence of the stiffness of an
AFO on the muscle-activation pattern of a subject suffering from an
anterior muscle insufficiency of the lower leg using a personalized
musculoskeletal model.
Materials and methods: Test subject was a 40-year old male suffering
from a hemiparetic anterior muscle insufficiency of the lower leg.
A musculoskeletal model of the lower limbs with 23 degrees of freedom
and 92 muscles was scaled in OpenSim to match the test subject’s
anthropometric data [1]. Muscle-definitions were adapted to simulate the
patients’ pathology.
A subject specific AFO was constructed using the selective laser sintering
technique [2]. The actual stiffness of the AFO was determined using finite
element analysis [3] and was 258 Nm/rad.
Marker trajectories of an AFO-gait were used to calculate kinematic
parameters and muscle-activation during gait using the musculoskeletal
model. The AFO was simulated as an angle-dependent torque around the
ankle with a neutral angle of 0°. The stiffness of the AFO was varied
between 150 and 350 Nm/rad in steps of 25 Nm/rad.
Results: Results showed alternating muscle-activation in the affected
lower leg with increasing AFO-stiffness. No clear correlation could be
found between AFO-stiffness and muscle-activation.
Page 39 of 56
Conclusion: An optimal AFO-stiffness in terms of muscle-activation can
be selected for the patient. It must be kept in mind that these results are
based on a calculation with a neutral AFO ankle position of 0°, and
changing this neutral angle, affects the results.
References
1. Delp SL, Anderson FC, Arnold AS, Loan P, Habib A, John CT, Guendelman E,
Thelen DG: OpenSim: Open-Source Software to Create and Analyze
Dynamic Simulations of Movement. IEEE Trans Biom Eng 2007,
54:1940-1950.
2. Pallari JHP, Dalgarno KW, Munguia J, Muraru L, Peeraer L, Telfer S,
Woodburn J: Design and Additive Fabrication of Foot and Ankle-Foot
Orthoses. Proceedings of the 21st Annual International Solid Freeform
Fabrication Symposium – An Additive Manufacturing Conference, 9-11 August
2010, Austin, Texas, USA.
3. Muraru L, Creylman V, Pallari J, Willemsen R, Vander Sloten J, Peeraer L:
Evaluation of functional parameters of ankle foot orthoses for different
materials and design characteristics. Proceedings of the 13th World
Congress of the International Society for Prosthetics and Orthotics, May 10-15
2010.
P7
Biomechanical assessment of the paediatric foot: using the current
evidence
Angela M Evans1,2*, Keith Rome1
1
Health & Rehabilitation Research Institute, AUT University, Auckland, 92006,
New Zealand; 2University of South Australia, Adelaide, 5000, Australia
Background: The paediatric flat foot is a frequent presentation in clinical
practice, a common concern to parents and continues to be debated. As
an entity, it is confused by varied classifications, the notion of wellintended prevention and unsubstantiated, if common, treatment [1]. The
paediatric flat foot proforma (p-FFP) is a standardized framework from
which to evaluate the paediatric flat foot [2].
Materials and methods: An algorithm, extending the p-FFP, has been
developed to direct assessment and management of the paediatric
flatfoot. Based upon best available evidence, this model includes joint
hypermobility, body weight and gender as relevant items to assess [3].
The normative data sets using the foot posture index are included and
recent reliability studies [4] have identified the value of the ankle lunge
test, Beighton scale and the lower limb assessment score in evaluation
joint range, hypermobility and quality of life (Table 1).
Results: A recent critical literature review has identified that the resting
calcaneal stance position (RCSP), navicular height and Foot Posture Index
(FPI-6) are the only three reliable measures of static foot posture [5].
Conclusions: Further research is required to establish a universal method
of assessment of paediatric foot posture. The relevance of static foot
posture to pain and shod gait function remains largely unsubstantiated in
children, and warrants further investigation.
References
1. Rome K, Ashford RL, Evans AM: Non-surgical interventions for paediatric pes
planus (Review). Cochrane Database Syst Rev 2010, 7, DOI:10.1002 /14651858.
CD006311.pub2.
2. Evans AM, Nicholson H, Zakaris N: The paediatric flat foot proforma (pFFP): improved and abridged following a reproducibility study. J Foot
Ankle Res 2009, 2:25.
Table 1(abstractP17) Inter-rater reliability: mean interrater ICC’s (95% CI’s) and SEM in children aged seven to
15 years (n=30)
Variable
ICC (95% CI)
Mean (SD)
SEM
Foot Posture Index
0.79 (0.38-0.94)
4.3 (2.7)
1.3
Lunge Test
0.83 (0.56-0.94)
43.7 (5.0)
2.9 deg
Beighton Scale
0.73 (0.42-0.88)
2.4 (1.2)
1.2
Lower Limb Assessment Score
0.78 (0.41-0.93)
9.7 (3.3)
2.5
3.
4.
5.
Page 40 of 56
Evans AM, Rome K: A Cochrane review of the evidence for non-surgical
interventions for flexible pediatric flat feet. Eur J Phys Rehabil Med 2011,
47:69-89.
Evans AM, Rome K, Peet L: The Foot posture index, Ankle lunge test,
Beighton scale and the Lower Limb Assessment Score in healthy
children: a reliability study. 2011, Under review.
Kneebone KA, Scutter SD, Evans AM: Clinical measures of paediatric foot
posture: a critical review. 2011, Under review.
P8
Pressure measurement devices: from technical assessment to clinical
performance
Claudia Giacomozzi1*, Moreno D’Amico2, Piero Roncoletta2
1
Dept. Of Technology and Health, Italian National Institute of Health (ISS),
Rome, Italy; 2Bioengineering and Biomedicine Company srl, Pescara, Italy
Background: Technical assessment of pressure measurement devices
(PMDs) should guarantee for their appropriate use in the clinics. The
study aims at proving the validity of the assessment methodology ISS
proposed [1], and at quantifying the impact of PMD performance on
clinical assessment.
Materials and methods: Three commercial PMDs were first assessed and
then compared during barefoot walking: PMDa and PMDb - resistive
technology, 1sens/cm2 – were assessed on-site, while PMDc – capacitive
technology, 4sens/cm2 - was tested on-the-bench and on-site [1]. The
PMDs were aligned on the floor to capture successive at-regimen steps of
the left foot of one trained volunteer; 10 complete steps were acquired in
both directions for each PMD; data were temporally normalised and
averaged; main kinetic parameters were extracted.
Results: Preliminary results (Table 1 and Figure 1): i) PMDc resulted
accurate and was used as a reference; ii) PMDa was found inaccurate onsite and delivered unreliable gait data; iii) PMDb was found accurate onsite but performed significantly worse than PMDc during gait.
Conclusions: To conclude: i) on-site assessment up to 250kPa proved to
be necessary but not sufficient to guarantee for a good PMD performance
during gait; ii) a thorough on-the-bench assessment is effective and
recommended; iii) use of PMDb data might be misleading in research and
risky in the clinics. The study is going on with the comparison among
other commercial PMDs and under a wide range of testing conditions.
References
1. Giacomozzi C: Hardware performance assessment recommendations and
tools for baropodometric sensor systems. Ann Ist Super Sanita 2010,
46:158-167.
2. Giacomozzi C: Potentialities and criticalities of Plantar Pressure
Measurements in the Study of Foot Biomechanics: Devices,
Methodologies and Applications. Biomechanics in Applications Intech:
Vaclav Klika , 1 2011, 249-274.
P9
Quantification of effectiveness prior to clinical application: the example
of silicone socks for diabetics
Claudia Giacomozzi1*, Jessica Crafoord2, Emanuela D’Ambrogi3, Luigi Uccioli3
1
Dept. of Technology and Health, Italian National Institute of Health (ISS),
Rome, Italy; 2Southern Älvsborg Hospital, Borås, Sweden; 3Dept. of Internal
Medicine, University of Rome “Tor Vergata”, Italy
Background: To avoid abnormal foot local loading while maintaining a
physiological foot biomechanics does represent a challenge in the
management of Diabetic foot and a valuable instrument to counter the
onset of the ulceration process. The authors hypothesized that silicone
socks may help in keeping dynamic peak pressures below risky values. The
study describes the methodology the authors used to assess the
effectiveness of the socks prior to the launch of the clinical application on
Diabetic patients.
Materials and methods: Silicone socks were tested on a healthy
volunteer during barefoot walking without and with socks; a calibrated
EMED pressure platform – capacitive technology, 4sens/cm2, accuracy 3%
- was used at 50Hz to acquire 30 at regimen steps for the left foot under
each condition; data were temporally normalised and averaged; main
kinetic parameters were extracted; vertical force values and curves were
used to characterize the volunteer’s foot biomechanics.
Results: Student’s t-test delivered p values <0.05 for duration and for the
3 relevant values of the force curve (load acceptance peak, midstance
valley, propulsion peak). Invariance of force curve was also verified
Table 1(abstractP8) Results from the on-the-bench and on-site assessment, and with respect to some clinically
relevant parameters
“gait” assessment: Peak
pressure (kPa)
“gait” assessment: Mean
pressure (kPa))
“gait” assessment:
Integral (kPa*s) [2]
PMD
ISS Full technical
under test assessment
ISS On-site partial
assessment
a
not performed
error >10% at 250kPa 100 (4)**
80 (2)**
39 (2)**
b
not performed
error < 5% at 250kPa 266 (12)*
191 (8)*
85 (9)*
C
accuracy error < 5% up error < 5% at 250kPa 744 (137)
to 1200kPa
367 (17)
152 (23)
* statistically different from PMDc corresponding data (p<0.05, also verified with respect to the ± 5% maximum error); ** statistically different from PMDb and
PMDc corresponding data (p<0.05, also verified with respect to the ± 5% maximum error).
Figure 1(abstract P8) Peak Pressure and Vertical Force curves obtained by the three tested PMDs; mean curve ± sd curve averaged over 10 left steps.
Page 41 of 56
Figure 1(abstract P9) Vertical Force and Peak Pressure curves obtained by barefoot walking without (black) and with (red) silicone socks (curves have
been averaged over 30 left steps).
through the linear regression test (r2 = 0.996; slope = 1.03) and the paired
t-test (p=0.543). Finally, the %RMSE calculated over the entire force curve
was equal to 2%. On the contrary, the analysis of peak pressure curve
and values showed that: i) curves were quite similar in shape but
different in values especially from load transfer to propulsion (r2 = 0.929;
slope = 0.70; %RMSE = 13%); ii) averaged peak pressure reduction was
165kPa, i.e. about 30% of the barefoot value and 13% of the device full
scale (1270kPa).
Conclusions: Difference in force <3% - the device accuracy level - and
difference in peak pressure and in %RMSE much > 3% proved the
potential effectiveness of the silicone socks in reducing local loading
without changing foot biomechanics. Tests under different walking
speeds, body weights and peak pressures are in progress.
for gastrocnemius (44%) and peroneals (18%). The only statistical IEMG
difference was gastrocnemius in Skechers with a 45% increase compared
to control (p=0.042).
Conclusions: Increased anterior-posterior CoP range in MBT is expected
due to the rocker profile [2]. Other conditions have footbeds with
intrinsic instability not an external feature, which may increase
effectiveness in gait. IEMG increased in experimental conditions showing
instability shoes increased total activation, however high variability masks
statistical differences. Inter-subject differences forms part of on-going
analysis. Limitations of single-leg balance mimicking gait are recognised;
increased duration of muscle activation is claimed by brands and fixedduration testing negates this.
Acknowledgements: The study was part-funded by FitFlop ltd.
References
1. Nigg B, Hintzen S, Ferber R: Effect of an unstable shoe construction on
lower extremity gait characteristics. Clin Biomech 2006, 21:82-88.
2. Landry S, Nigg B, Tecante K: Standing in an unstable shoe increases
postural sway and muscle activity of selected smaller extrinsic foot
muscles. Gait Posture 2010, 32:215-219.
P10
Single-leg balance in “instability” footwear
Carina Price, Laura Smith, Philip Graham-Smith, Richard Jones*
Manchester, M6 6PU, UK
P11
The effects of using a lateral wedge insole on knee loading during
ascending and descending stairs
Amneh Alshawabka, Richard Jones*, Sarah Tyson
Manchester, M6 6PU, UK
Background: The concept of instability footwear is to reduce stability,
increase muscle activation and “tone”. Recently numerous brands have
developed instability footwear for significant sales. Despite extensive
marketing claims there are few empirical studies quantifying effects of
instability footwear on muscle activity or motion in healthy individuals
aside from Masai Barefoot Technology (MBTTM) [1,2]. The aim of the study
was to quantify instability in single-leg standing in a variety of
commercially available instability sandals.
Methods: Fifteen female subjects participated (age: 29±6.7 years, mass:
62.6±6.9 kg, height: 167.1±4.2 cm). The protocol quantified Centre of
Pressure (CoP) excursion (Kistler) and lower extremity integrated muscle
activity (IEMG) (Noraxon) for three thirty second single-leg standing trials
in four experimental conditions and one control (Earth FootwearTM). The
instability footwear conditions were FitFlopTM, MBTTM, Reebok Easy-ToneTM
and Skechers Tone-UpsTM. IEMG is presented normalised to control.
Results: Repeated measures ANOVA revealed significant differences in
CoP with MBT having significantly greater anterior-posterior range than
Control (p=0.012), FitFlop (p=0.033) and Skechers (p=0.014) (Table 1).
Medial-lateral ranges were consistent between conditions. Testing
identified increased CoP velocity in anterior-posterior and medial-lateral
directions in MBT compared to other conditions, but neither reached
significance. IEMG was higher in instability shoes with average increases
Background: Stair climbing demands, as compared to walking level, a
greater range of motion in the lower extremity accompanied by about six
times more load on knee joint [1]. Consequently, pain while climbing stairs
is the first complaint in patients with knee osteoarthritis (OA) [2]. The use of
lateral wedge insoles aims to decrease medial knee compartment loading
by reducing the peak external knee adduction moment (EKAM) during
walking [4]. The purpose of this study is to assess the biomechanical effects
of wearing lateral wedge insoles on EKAM during stair climbing in elders
with and without knee OA.
Methods: Thirty healthy subjects (21 females, 9 males; age (45.7±5.6
years)) and eight patients with mild knee OA (5 females, 3 males; age
(47.3±3)) participated in the study. Subjects performed five trials of stepover-step stairs ascent and descent. Two conditions were investigated:
(a) control (Standard shoe) (b) 5 degrees Salford Insole lateral wedge (LW)
insoles. Kinematic and kinetic data were collected for the lower extremity
Table 1(abstractP10) CoP and IEMG results for the footwear conditions
Control
Fitflop
MBT
Reebok
Skechers
CoP medial-lateral range (mm)
36.5 (±7.8)
35.5 (±4.1)
34.9 (±3.8)
34.6 (±4.7)
34.0 (±4.3)
CoP anterior-posterior range (mm)
49.6 (±11.1)
53.0 (±8.4)#
64.0 (±10.9)*,#
50.3 (±15.0)
49.3 (±12.3)#
CoP medial-lateral velocity (mm.s-1)
29.8 (±4.8)
28.7 (±4.9)
30.0 (±6.1)
29.3 (±5.6)
28.5 (±6.2)
CoP anterior-posterior velocity (mm.s-1)
26.4 (±3.6)
27.7 (±4.7)
28.4 (±5.0)
27.9 (±4.9)
26.8 (±5.1)
Medial gastrocnemius IEMG (%)
-
1.37 (±0.52)
1.53 (±0.75)
1.39 (±0.64)
1.45 (±0.51)*
Peroneals IEMG (%)
-
1.19 (±0.33)
1.21 (±0.31)
1.15 (±0.22)
1.16 (±0.21)
* Denotes significant difference between control and instability condition (p<0.05).
#
Denotes significant difference between instability conditions (p<0.05).
Page 42 of 56
Table 1(abstractP11) 1st EKAM peak, KAAI and Subtalar eversion angle results for healthy and OA Subjects during
ascending (AS) and descending (DS) stairs
Parameters
1st peak EKAM (Nm/Kg)
KAAI (Nm/Kg/s)
Subtalar peak eversion (degrees)
Mean ± (SD)
Mean ± (SD)
Control (Healthy)
LW (Healthy)
Control (OA)
AS
.385 (.15 )
.357 (.14)
.394 (.13)
.366 (.12)
DS
.408 (.11)
.388 (.10)
.364 (.06)
.334 (.05)
AS
.228 (.15)
.207 (.14)
.189 (.06)
.174 (.06)
DS
.228 (.08)
.212 (.08)
.204 (.04)
.186 (.04)
AS
-5.71 (2.4)
-6.1 (2.9)
-4.41 (.62)
-4.82 (.70)
DS
-6.36 (2.3)
-7.06 (2.5)
-4.42 (1.2)
-5.11 (1.5)
using a motion capture system (QTMTm) and two force plates (AMTI force
platform stairway). Repeated measures ANOVA and Friedman’s ANOVA
were used for statistical analysis.
Results: During ascending stairs, LW significantly reduced the EKAM in
early stance (p<.05) and the knee adduction angular impulse (KAAI)
(p<.05). Similarly, the EKAM and KAAI had been significantly reduced
(p<.05) while wearing LW during descending stairs. Both groups had
significantly greater degree of subtalar eversion with LW than in the
control condition (Table 1).
Conclusions: Lateral wedge insoles consistently reduced the overall
magnitude of EKAM during ascending and descending stairs which has
been strongly correlated to decreasing medial compartment loading at
the knee joint. Thus, these results give the first indication that that
lateral wedge insoles may be useful in decreasing pain levels for
patients with knee OA during stair climbing. Further long-term studies
are warranted.
References
1. Andriacchi TP, et al: A study of lower-limb mechanics during stairclimbing. The Journal of Bone and Joint Surgery 1980, 62(5):749.
2. Costigan PA, Deluzio KJ, Wyss UP: Knee and hip kinetics during normal
stair climbing. Gait & posture 2002, 16(1):31-37.
3. Arden NK, et al: Osteoarthritis and risk of falls, rates of bone loss, and
osteoporotic fractures. Arthritis & Rheumatism 1999, 42(7):1378-1385.
4. Jones RK, et al: Does increased loading occur on the contralateral side in
medial knee osteoarthritis and what impact do lateral wedges have on
this? Osteoarthritis Cartilage 2011, Suppl 1: S176.
P12
Forefoot deformation during the stance phase of normal gait
Saartje Duerinck1,2*, Friso Hagman3, Ilse Jonkers4, Peter Vaes2, Peter Van Roy1
1
Department of Experimental Anatomy, Vrije Universiteit Brussel, Brussels,
1090, Belgium; 2Department of Physical Therapy, Vrije Universiteit Brussel,
Brussels, 1090, Belgium; 3Department of Human Biomechanics & Biometrics,
LW (OA)
Vrije Universiteit Brussel, Brussels, 1090, Belgium; 4Department of Biomedical
Kinesiology, Katholieke Universiteit Leuven Belgium, Leuven, 3000, Belgium
Background: During human walking the ankle-foot complex executes
seemingly contradictory functions: (1) stabilization of the human body at
initial contact, (2) shock absorption during early stance [1-3], (3) Storing
elastic energy during midstance and (4) providing a strong lever for push
of during final stance [1]. This quadrupled function inevitably demands a
transfer from a flexible and compliant foot towards a rigid lever [1].
Despite the viable role of the forefoot in this transfer, knowledge
concerning the deformation of the forefoot is limited. The aim of this
study is to provide a more detailed description of deformation occurring
at the level of the forefoot during the stance phase of normal human
walking.
Materials and methods: Using a seven-camera motion capture system
(250Hz), a pressure platform (500Hz) and a forceplate (1250Hz), we
measured forefoot deformation through kinematic and pressure related
outcome measures in 60 healthy subjects.
Results: Small but significant changes in intermetatarsal distance are
established during stance phase, with the largest change occurring
between metatarsal head II/III and V (Table 1). The changes in
intermetatarsal distance and metatarsal arch height show slightly
different patterns. Both patterns are characterized by a rapid increase in
distance during initial stance, reaching a stable platform throughout
midstance. At the end of stance phase the intermetatarsal distances
rapidly decrease to baseline, whereas the metatarsal arch height
increases till a maximum at heel off (Figure 1-5).
High correlation values (>0.7 or <-0.7) are found between temporal
pressure and temporal kinematic parameters.
Conclusion: Through stance the forefoot deforms according to a specific
pattern, which is predominantly determined through forefoot-ground
interaction. In addition, the changes in forefoot kinematics in combination
Table 1(abstractP12) Parameters characterizing the changes in medio-lateral arch height and mutual distances
between metatarsal head I, II/III and V and metatarsal base I and V during stance phase and for the different
subphases
StPh (mm)
HC (mm)
MF (mm)
MS (mm)
IPO (mm)
FPO (mm)
Max. MedioLat Height
Min. MedioLat Height
1.13 ± 0.08
85.95 ± 8.95
0.87 ± 0.07
4.39 ± 2.50
0.87 ± 0.06
12.34 ± 3.32
1.01 ± 0.04
47.25 ± 12.02
1.13 ± 0.08
87.39 ± 7.73
1.05 ± 0.10
95.88 ± 1.27
Max. distance HMTI-HMTV
1.01 ± 0.01
0.92 ± 0.02
0.96 ± 0.02
1.01 ± 0.01
1.00 ± 0.01
0.94 ± 0.02
Min. distance HMTI-HMTV
0.90 ± 0.02
0.90 ± 0.02
0.92 ± 0.02
0.96 ± 0.02
0.94 ± 0.02
0.91 ± 0.02
Max. distance HMTI-HMTII/III
1.01 ± 0.04
0.94 ± 0.04
0.95 ± 0.04
1.01 ± 0.03
1.01 ± 0.02
0.97 ± 0.04
Min. distance HMTI-HMTII/III
0.91 ± 0.04
0.92 ± 0.04
0.93 ± 0.04
0.95 ± 0.04
0.97 ± 0.04
0.93 ± 0.04
Max. distance HMTII/III- HMTV
1.01 ± 0.04
0.89 ± 0.05
0.94 ± 0.05
1.01 ± 0.04
1.01 ± 0.04
0.93 ± 0.04
Min. distance HMTII/III- HMTV
0.87 ± 0.05
0.87 ± 0.05
0.89 ± 0.05
0.94 ± 0.48
0.93 ± 0.04
0.90 ± 0.04
Max. distance BMTI-BMTV
Min. distance BMTI-BMTV
1.00 ± 0.01
0.97 ±0.01
0.99 ± 0.01
0.97 ± 0.01
0.99 ± 0.01
0.99 ± 0.01
1.00 ± 0.01
0.99 ± 0.01
1.00 ± 0.01
0.98 ± 0.01
1.00 ± 0.01
0.97 ± 0.01
Legend: StPh = stance phase, HC = heel contact, MF = metatarsal forming, MS = midstance, IPO = initial propulsion, FPO = final propulsion, max. = maximum,
min. = minimum, HMT = head metatarsal, BMT = base metatarsal.
Figure 1(abstract P12) Changes in distance between metatarsal head
I - V, I - II/III and II/III – V and in metatarsal arch height: Changes in
distance between metatarsal head I and metatarsal head V throughout
stance phase for the left foot.
Figure 2(abstract P12) Changes in distance between the base of
metatarsal I and the base of metatarsal V throughout stance phase for the
left foot.
Page 43 of 56
Figure 4(abstract P12) Changes in distance between metatarsal head
II/III and metatarsal head V throughout stance phase for the left foot.
Figure 5(abstract P12) Changes in medio-lateral arch height
throughout stance phase for the left foot.
with temporal contact data argue the existence of a mediolateral
metatarsal arch and suggest the existence of an inverse arch during
metatarsal forming and final propulsion phase.
Acknowledgement: The preparation of this abstract was funded by the
Vrije Universiteit Brussel (i.e., GOA 59)
References
1. Jenkyn TR, Anas K, Nichol A: Foot segment kinematics during normal
walking using a multisegment model of the foot and ankle complex. J
Biomech Eng 2009, 131:034504.
2. Winter DA: Energy generation and absorption at the ankle and knee during
fast, natural, and slow cadences. Clin Orthop Relat Res 1983, 131:147-154.
3. Ren LHD, Ren LQ, Nester C, Tian LM: a phase-dependent hypothesis for
locomotor functions of human foot complex. J Bionic Eng 2008, 5:175-180.
Figure 3(abstract P12) Changes in distance between metatarsal head I
and metatarsal head II/III throughout stance phase for the left foot.
P13
Validation of a one degree-of-freedom spherical model for kinematics
analysis of the human ankle joint
Nicola Sancisi1, Vincenzo Parenti-Castelli1, Benedetta Baldisserri1,
Claudio Belvedere2, Matteo Romagnoli2, Valentina D’Angeli2, Alberto Leardini2*
1
Department of Mechanical Engineering-DIEM, University of Bologna, 40136
Bologna, Italy; 2Movement Analysis Laboratory, Istituto Ortopedico Rizzoli,
40136 Bologna, Italy
Background: During passive motion, the human tibiotalar (ankle) joint
behaves as a single degree-of-freedom (1DOF) system [1,2]. In these
conditions, fibres within the ligaments remain nearly isometric throughout
the flexion arc and articular surfaces nearly rigid. Relevant theoretical
models are showing that the ligaments and the articular surfaces act
together as mechanisms to control the passive joint kinematics [3-5].
Kinematic measurements and corresponding model predictions also
revealed that the instantaneous screw axes of passive motion pass near to
a single point, hereinafter called pivot point [5]. The present study
investigates the extent to which this motion is spherical-like.
Materials and methods: A 1DOF Spherical Parallel Mechanism is
analyzed, based both on joint anatomy and kinematics: the calcanealfibular and tibio-calcaneal ligaments are modelled as binary links of
constant length, and relevant bones are connected by a spherical pair
centred at the pivot point [5]. Geometrical data and reference motion
were obtained from experiments in 5 amputated lower limbs, free from
anatomical defects. Anatomical landmarks, articular surfaces and ligament
origins and insertions were digitized. Passive dorsi-/plantar-flexion cycles
were performed and relevant bone motion was recorded by a standard
stereo-photogrammetric device. The pivot point was obtained by
searching the point with the least mean squared distance from the
instantaneous screw axes of passive motion. The closure equations were
solved to obtain the simulated motion of the joints, to compare it with
the original experimental motion.
Results: In all specimens, the model replicated passive motion with a
very good precision (Figure 1).
Conclusions: The passive motion of the ankle joints can be
approximated well by a 1DOF spherical mechanism, despite the simple
structure of this model. Replication of the original experimental motion
can be a little worse than using previous mechanisms [4] (Figure 1), but
computational costs, mechanical complexity and numerical instabilities
are significantly reduced.
References
1. O’Connor JJ, et al: Review: Diarthrodial Joints-Kinematic Pairs,
Mechanisms or Flexible Structures? Comput Methods Biomech Biomed
Engin 1998, 1:123-150.
Page 44 of 56
2.
3.
4.
5.
Leardini A, et al: Kinematics of the human ankle complex in passive
flexion; a single degree of freedom system. J Biomech 1999, 32:111-118.
Leardini A, et al: A geometric model of the human ankle joint. J Biomech
1999, 32:585-591.
Franci R, et al: A new one-DOF fully parallel mechanism for modelling
passive motion at the human tibiotalar joint. J Biomech 2009,
42:1403-1408.
Franci R, Parenti-Castelli V: A one-degree-of-freedom spherical wrist for
the modelling of passive motion of the human ankle joint. IAK 2008 Lima
2008, 1-13.
P14
The effect of prior compression tests on the plantar soft tissue
compressive and shear elastic properties
Shruti Pai1, Paul T Vawter2, William R Ledoux1,2,3*
1
VA RR&D Center of Excellence for Limb Loss Prevention and Prosthetic
Engineering, Seattle, Washington, 98108, USA; 2Mechanical Engineering,
University of Washington, Seattle, Washington, 98195, USA; 3Orthopaedics
and Sports Medicine, University of Washington, Seattle, Washington, 98195,
USA
Background: Changes in the shear plantar soft tissue properties with
diabetes likely play a role in plantar ulceration, yet little is known about
these characteristics. We recently conducted in vitro shear tests on
specimens previously tested in compression to characterize the tissue
under both these loading modes. However, previously tested specimens
might not provide representative mechanical properties as prior testing
may have altered the tissue. The purpose of this study was to test the
effect of prior compression testing on the plantar soft tissue shear and
compressive properties using paired specimens in a two-part study.
Materials and methods: Four pairs of cylindrical specimens (n=8) were
isolated per previous methods [1] from the calcaneus and lateral midfoot
from three fresh-frozen, non-diabetic older cadaveric donors. In the first
Figure 1(abstract P13) The three displacements of a typical specimen, obtained from experiments (black), a previous model (red) and the spherical one
(blue).
Page 45 of 56
Reference
1. Pai S, Ledoux WR: The compressive mechanical properties of diabetic
and non-diabetic plantar soft tissue. J Biomech 2010, 43:1754-1760.
Table 1(abstractP14) Mean [SE] nonlinear elastic
compressive and shear data parameters
U
C
Peak compressive strain (%)
39.99 [3.6e-3]
39.98 [6.7e-3]
p*
0.3
Peak compressive stress (kPa)
31.6 [6.3]
12.9 [4.5]
0.0002
Compressive modulus (kPa)
Compressive energy loss (%)
267 [72]
38.2 [1.4]
87 [35]
37.8 [1.6]
0.0031
0.7
Peak shear strain (%)
80.9 [1.6e-2]
80.9 [1.6e-2]
0.3
Peak shear stress (kPa)
9.0 [1.5]
9.9 [2.0]
0.6
Initial shear modulus (kPa)
58 [19]
61 [16]
0.8
Toe shear modulus (kPa)
5.4 [0.7]
5.3 [0.9]
0.9
Final shear modulus (kPa)
21.9 [4.0]
25.4 [5.6]
0.3
Shear energy loss (%)
48.0 [4.2]
42.8 [4.2]
0.2
p<0.05 indicates significance for linear mixed effects regression; U = previously
untested, C = compression tested.
part of the study, one specimen from each pair was subject to
compressive loading with modifications to compare properties before
and after testing. In the second part, both paired specimens were subject
to shear loading, i.e., both the previously compression tested from the
first part and the previously untested specimens.
Results: The results (Table 1) of the first part demonstrated that prior
compression testing affects the plantar soft tissue compressive properties
by reducing peak stress and modulus by two to three times, although
additional testing is needed since these results were likely confounded by
stress softening effects. In contrast, in Part B, none of the elastic shear
properties were affected by prior testing in compression.
Conclusions: This study demonstrates that prior compression testing of
the plantar soft tissue may alter the compressive properties. However,
since the shear parameters were not affected by prior testing in
compression, shear tests using previously compression tested specimens
should provided representative properties.
Figure 1(abstract P15) The simplified AI visual assessment tool.
P15
Visual categorisation of the Arch Index: a simplified measure of foot
posture in older people
Hylton B Menz*, Mohammad R Fotoohabadi, Elin Wee, Martin J Spink
3086, Australia
Background: Many foot posture measurement approaches are not
suitable for routine use as they are time-consuming or require specialised
equipment and/or clinical expertise. The objective of this study was to
develop and evaluate a simple visual assessment tool for foot posture
assessment based on the Arch Index (AI) [1].
Materials and methods: Fully weightbearing footprints from 602 people
aged 62 to 96 years were obtained using a carbon paper imprint material,
and cut-off AI scores dividing participants into three categories (high,
normal and low) were determined. A visual tool was created using
representative examples for the boundaries of each category (Figure 1).
Two examiners used the tool to independently grade the footprints of 60
participants (20 for each of the three categories, randomly presented), and
then repeat the process two weeks later. Inter- and intra-tester reliability
were determined and the validity of the examiner’s assessments was
evaluated by comparing their categorisations to the actual AI score.
Results: Inter- and intra-tester reliability of the examiners was almost
perfect (percentage agreement = 93 to 97%; Spearman’s rho = 0.91 to
0.95, and weighted kappas = 0.85 to 0.93). Examiner’s scores were
strongly correlated with actual AI values (Spearman’s rho = 0.91 to 0.94
and significant differences between all categories with ANOVA; p<0.001)
and AI categories (percentage agreement = 95 to 98%; Spearman’s rho =
0.89 to 0.94, and weighted kappas = 0.87 to 0.94). There was a slight
tendency for examiners to categorise participants as having higher arches
than their AI scores indicated.
Conclusions: Foot posture can be quickly and reliably categorised as high,
normal or low in older people using a simplified visual categorisation tool
based on the AI.
Reference
1. Cavanagh PR, Rodgers MM: The arch index: a useful measure from
footprints. J Biomech 1987, 20:547-551.
P16
Plantar pressures and relative metatarsal lengths in older people with
and without forefoot pain
Hylton B Menz1*, Mohammad R Fotoohabadi1, Shannon E Munteanu1,2,
Gerard V Zammit1,2, Mark F Gilheany1
1
3086, Australia; 2Department of Podiatry, La Trobe University, Bundoora,
Victoria 3086, Australia
Background: It has been suggested that plantar forefoot pain
(‘metatarsalgia’) may be caused by the presence of abnormally long
lesser metatarsals leading to excessive loading of the metatarsal heads
when walking. However, evidence to support this proposed mechanism is
limited. Therefore, the objective of this study was to determine whether
plantar pressures during gait and the relative lengths of the lesser
metatarsals differ between older people with and without plantar
forefoot pain.
Materials and methods: Dynamic plantar pressure assessment during
walking was undertaken using the Tekscan MatScan® system in 118
community-dwelling older people (44 males and 74 females, mean age
74.0 years, standard deviation [SD] 5.9), 43 (36%) of whom reported
current or previous plantar forefoot pain. Seven individual “masks” were
constructed to determine peak pressures under the hallux, the lesser
toes, metatarsal head 1, metatarsal head 2, metatarsal heads 3 to 5, the
midfoot and the heel (see Figure 1). The relative lengths of metatarsals
1 to 5 were determined from weightbearing dorsoplantar x-rays using the
Maestro [1] and Coughlin [2] techniques.
Results: There were no differences between the groups for age,
bodyweight or walking speed. Participants with current or previous
plantar forefoot pain exhibited significantly greater peak plantar pressure
under metatarsal heads 3 to 5 (1.93 [SD 0.41] versus 1.74 [0.48] kg/cm2,
p=0.032; Cohen’s d = 0.42 - medium effect). However, there were no
differences in relative metatarsal lengths between the groups.
Conclusions: Older people with current or previous forefoot pain display
greater peak plantar pressures under the lateral metatarsal heads when
Figure 1(abstract P16) Mask template used for plantar pressure analysis.
Page 46 of 56
walking, but do not exhibit relatively longer lesser metatarsals. Other
factors may be responsible for the observed pressure increase, such as
reduced range of motion of the metatarsophalangeal joints and increased
stiffness of plantar soft tissues.
References
1. Maestro M, Besse JL, Ragusa M, Bertonnaud E: Forefoot morphotype study
and planning method for forefoot osteotomy. Foot Ankle Clin 2003,
8:695-710.
2. Coughlin MJ: Crossover second toe deformity. Foot Ankle 1987, 8:29-39.
P17
Changes in foot posture and function following total knee replacement
surgery
Pazit Levinger1*, Hylton B Menz1, Adam D Morrow1, Julian A Feller1,
John R Bartlett2, Mohammad R Fotoohabadi1, Neil Bergman2
1
Musculoskeletal Research Centre, La Trobe University, Melbourne, VIC, 3086
Australia; 2Warringal Medical Centre, Melbourne, Vic, 3084, Australia
Background: Knee malalignment and variations in foot posture and
function affect the forces transmitted through the knee joint and are
associated with knee pain and medial tibiofemoral cartilage damage [1].
However, it is unclear whether altered foot posture and function are a
compensatory mechanism to accommodate knee malalignment. Therefore,
this study investigated changes in foot posture and function after
realignment of the knee following total knee replacement (TKR) in people
with medial compartment knee OA.
Materials and methods: Nineteen patients (6 females and 13 males;
mean age 67.5 ± 5.9 years, height 169.1 ± 9.9 cm, mass 87.9 ± 11.8 kg
and BMI 31.0 ± 5.7 kg/m2) diagnosed with predominantly medial
compartment knee OA who were scheduled for TKR surgery participated
in the study, and were tested prior to and 12 months after TKR. Foot
Posture Index (FPI) and arch index were measured as well as motion of
the tibia, rearfoot and forefoot using a 3D motion analysis system
incorporating a multisegment foot model (Oxford Foot Model).
Results: Significant increases in tibial external rotation (-18.7± 7.0° vs
-22.5 ± 8.7°, p = 0.002) and tibial transverse plane range of motion (ROM)
(-9.1 ± 4.6° vs -11.4 ± 6.1°, p = 0.0028) were observed following the
surgery. An increase in rearfoot ROM in the frontal plane (8.6 ± 2.6° vs
10.4 ± 2.7°, p = 0.002) and a decrease in rearfoot transverse plane ROM
(8.7 ± 5.3° vs 5.9 ± 4.1°, p = 0.038) were observed. No significant
differences were found between pre and post-surgery in the FPI and or
the arch index.
Conclusions: Following TKR, there is an increase in the ROM of the
rearfoot in the frontal plane, but no change in static foot posture
suggesting that rearfoot motion compensates for changes in the
alignment of the knee.
Reference
1. Wada M, Maezawa Y, Baba H, Shimada S, Sasaki S, Nose Y: Relationships
among bone mineral densities, static alignment and dynamic load in
patients with medial compartment knee osteoarthritis. Rheumatology
2001, 40:499-505.
P18
Abstract Withdrawn
Abstract Withdrawn:
P19
Idiopathic peripheral neuropathy increases fall risk in a populationbased cohort study of older adults
Jody L Riskowski1,2*, Lien Quach1, Brad Manor2,3, Hylton B Menz1,2,4,
Lewis A Lipsitz1,2,3, Marian T Hannan1,2
1
Institute for Aging Research, Hebrew SeniorLife, Boston, Massachusetts
02131-1011, USA; 2Harvard Medical School, Boston, Massachusetts 021156092, USA; 3Gerontology and Interdisciplinary Medicine and Biotechnology,
Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115-6092,
USA; 4Musculoskeletal Research Centre, La Trobe University, Bundoora,
Victoria 3086, Australia
Background: Peripheral neuropathy (PN) is often associated with specific
diseases; however, research suggests that idiopathic PN is prevalent in
older adult populations [1]. Foot ulceration is the traditional medical
Figure 1(abstract P19) IRR between PN and falls.
Page 47 of 56
concern with PN, but people with PN may also have disproportionately
more falls [2]. Therefore, our objective was to evaluate associations
between PN and prospectively-ascertained falls in older adults from the
population-based MOBILIZE Boston Study.
Materials and methods: Participants included 760 MOBILIZE Boston
Study members. PN was assessed using Semmes-Weinstein monofilament
testing [3], applying the modified Health ABC Study method [4,5]. Three
PN status groups were defined: (i) no PN (referent), (ii) PN and known
disease associated with PN (e.g., diabetes, autoimmune disease) (K-PN),
and (iii) idiopathic PN (I-PN). Falls were tracked through monthly fall
calendars over a mean 2.8 (range 1.4-4.3) year follow-up period.
Unadjusted and adjusted (age, body mass index, physical activity, prior
year fall, visual acuity, depression and number of medications) genderspecific negative binomial regression models determined associations
between PN and falls.
Results: I-PN was associated with a higher fall incidence in men (incidence
rate ratio [IRR] 1.76 [95% confidence interval 1.00–3.09]; Figure 1) and
women (1.69 [1.06–2.70]). These higher IRRs with I-PN persisted even after
covariate adjustment in women (1.68 [1.09–2.60]) and men (1.70 [0.90–
3.22]), with men’s confidence interval widening. K-PN was not associated
with an increased incidence of falling in men and had weak, nonsignificant effect in women.
Conclusions: Idiopathic PN is an independent fall risk factor for women
and men, suggesting that PN assessments should be included in fall risk
evaluations. Future work to investigate mechanisms through which PN
increases fall risk and to evaluate interventions that target fall risk in
individuals with PN, such as insoles with low-grade vibrations [6], is
needed.
References
1. Mold JW, Vesely SK, Keyl BA, Schenk JB, Roberts M: The prevalence,
predictors, and consequences of peripheral sensory neuropathy in older
patients. J Am Board Fam Pract 2004, 17:309-318.
2. Richardson JK, Hurvitz EA: Peripheral neuropathy: a true risk factor for
falls. J Gerontol A Biol Sci Med Sci 1995, 50:M211-215.
3. Perkins BA, Olaleye D, Zinman B, Bril V: Simple screening tests for
peripheral neuropathy in the diabetes clinic. Diabetes Care 2001,
24:250-256.
4.
5.
6.
Strotmeyer ES, Cauley JA, Schwartz AV, de Rekeneire N, Resnick HE,
Zmuda JM, Shorr RI, Tylavsky FA, Vinik AI, Harris TB, et al: Reduced
peripheral nerve function is related to lower hip BMD and calcaneal
QUS in older white and black adults: the Health, Aging, and Body
Composition Study. J Bone Miner Res 2006, 21:1803-1810.
Leveille SG, Jones RN, Kiely DK, Hausdorff JM, Shmerling RH, Guralnik JM,
Kiel DP, Lipsitz LA, Bean JF: Chronic musculoskeletal pain and the
occurrence of falls in an older population. JAMA 2009, 302:2214-2221.
Liu W, Lipsitz LA, Montero-Odasso M, Bean J, Kerrigan DC, Collins JJ: Noiseenhanced vibrotactile sensitivity in older adults, patients with stroke,
and patients with diabetic neuropathy. Arch Phys Med Rehabil 2002,
83:171-176.
P20
The influence of corpulence on the mechanical properties of the
human heel fat pad in elderly
Frank Lindner*, Günther Schlee, Thomas L Milani
Institute of Sport Science, Human Locomotion, Chemnitz University of
Technology, Chemnitz, Free State of Saxony, 09107, Germany
Background: The human heel fat pad (HFP) is an effective shock absorber
[1]. A remodelling of body fat begins from the fifth decade of the human life.
Diet may negatively influence this distribution and consequently lead to
corpulence in elderly persons. Alcantara and colleges reported that fat
content in the HFP increases with obesity [2]. Hence, the purpose of this
investigation was to determine the effect of corpulence on the mechanical
properties of the HFP in elderly. We hypothesized, that corpulence alters
mechanical properties of the HFP compared to normal weighted elderly
persons.
Materials and methods: Twenty-three healthy elderly corpulent (age 61
± 6 yrs, height 171 ± 8 cm, BMI 28 ± 2, weight 82 ± 7 kg) and nineteen
non-corpulent men and women (age 61 ± 7 yrs, height 168 ± 8 cm, BMI 23
± 1, weight 65 ± 7 kg) took part in the experiment. A loading device was
Page 48 of 56
used for in vivo testing of the HFP (Figure 1). Parameters were measured
under two different impact velocities (low 2 mm/s, fast 10 mm/s). Several
mechanical variables (unloaded and loaded HFP thickness, stiffness S,
elasticity ε) were calculated.
Results: Thickness variables of corpulent subjects were significantly
higher compared to the non-corpulent. The stiffness was found to have a
nonlinear behaviour in which corpulent subjects show lower stiffness in
the final stage. There was no significant difference in ε.
Conclusions: Increased HFP thickness is an adaption process to increased
body weight, suggesting that an accumulation of fat cells with good blood
supply at micro chamber structure may have occurred. This process protects
the macro chamber structure of the HFP against overload that is transferred
by micro chambers. Therefore, the micro chamber structure of corpulent
elderly may be mechanically more sensitive and damageable than in noncorpulent subjects.
References
1. Robbins SE, Gouw GJ, Hanna AM: Running-related injury prevention through
innate impact moderating behavior. Med Sci Sport Exer 1989, 21:130-139.
2. Alcántara E, Forner A, Ferrús E, García AC, Ramiro J: Influence of age,
gender, and obesity on the mechanical properties of the heel pad
under walking impact conditions. J Appl Biomech 2002, 18:335-345.
P21
Static examination of the range of ankle joint dorsiflexion is not related
to dynamic foot kinematics
Hannah Jarvis*, Christopher J Nester, Peter P Bowden, Richard K Jones,
Anmin Liu
School of Health, Sport and Rehabilitation Sciences, Centre for Health, Sport
and Rehabilitation Sciences Research, University of Salford, Salford, M6 6PU,
UK
Background: Our aim was to (1) investigate whether the range of ankle
dorsiflexion measured in a static examination relates to the sagittal plane
Figure 1(abstract P20) shows the loading device (measurement accuracy of the system is 0.09 mm and 18 kPa). Details on design of the loading device:
B1 foundation, B2 carriage, B3 tower of weights, B4+B5 separated footrest with integrated GRF-platform (1000 Hz) to measure Vertical GRF, M
microprocessor controlled step motor for the velocity controller of the carriage, O leg brace; P1+P2 emed pedography platform (resolution 2 sensors/
cm², frequency 50 Hz), U1 Ultrasound device (axial resolution 0.07 mm), U2 fixture with integrated ultrasound transducer.
motion within the foot during walking and (2) investigate the popular
clinical theory that individuals with limited ankle joint dorsiflexion (in a
static examination [1,2]) will demonstrate increased rearfoot eversion
during walking [1-3].
Materials and method: The static range of ankle joint dorsiflexion
was measured with the knee flexed and extended (n=100). Dynamic
foot kinematics were measured for the tibia, calcaneus, midfoot, lateral
forefoot, medial forefoot and hallux, and 13 parameters derived
to characterise foot kinematics (right foot only). The relationship
between static range of ankle joint dorsiflexion and sagittal plane
motion within the foot during walking was examined using Pearsons
correlation. An independent t-test (p<0.05) was used to compare
dynamic foot kinematics in subjects exhibiting <10° and >15° of static
ankle joint dorsiflexion (n=83, n=7 knee extended, n=40, n=23 knee
flexed).
Results: The range of ankle joint dorsiflexion measured statically was
poorly correlated [4] with all 13 parameters describing dynamic foot
kinematics (all r values<-0.254, p<0.05). Individuals with <10° of static
ankle joint dorsiflexion exhibited less eversion of the calcaneus relative to
the tibia between forefoot loading and heel lift (mean, 2.1° eversion
motion compared to 4.8° eversion motion (knee extended), and 1.6°
eversion motion compared to 3.5° (knee flexed)). Also, there was less
plantarflexion of the medial forefoot relative to the midfoot between heel
lift and toe off (mean value of 13.1° compared to 18.5°).
Conclusions: Static assessment of ankle joint dorsiflexion does not
appear to relate to dynamic foot kinematics. The differences in foot
kinematics in those with <10 or >15 of ankle joint dorsiflexion measured
from static examination contradict a key principle of the current clinical
paradigm from Root et al [1,2].
References
1. Root ML, Orien WP, Weed JH, Hughes RJ: Biomechanical examination of
the foot. Los Angeles: Clinical Biomechanics Corp 1971.
2. Root ML, Orien WP, Weed JH, Hughes RJ: Normal and abnormal function
of the foot. Los Angeles: Clinical Biomechanics Corp 1977.
3. Cornwall MW, McPoil TG: Effect of ankle dorsiflexion on rearfoot motion
during walking. J Am Podiatr Med Assoc 1999, 89:272-277.
4. Portney LG, Watkins MP: Foundations of clinical research. Applications to
practice. Connecticut: Appleton and Lange, 3 2009.
Page 49 of 56
preference for prefabricated orthoses. Research has failed to identify major
differences between the two types of orthosis [1-4]. This project aimed to
design, develop and evaluate a new anti-pronation foot orthosis. The
project was initiated following observations that many prefabricated
orthoses failed to incorporate the design principles used in custom made
orthoses and the lack of evidence for the effect of prefabricated orthoses
on foot pronation.
Materials and method: The project comprised three stages. In stage 1
(definition of problem) professional, patient, consumer and retail opinions
of existing foot orthoses was sought through unstructured interviews.
This produced a technical specification for the new orthosis. In stage 2
(development of orthosis), 80 foot casts were rationalised through
observation of cast shape and testing of prototype orthoses to identify a
‘model’ foot shape. Bespoke orthotic materials were formulated and
tested to compare durability and stiffness to existing orthosis materials. In
stage 3 (evaluation), rearfoot inversion/eversion was measured in 30
people walking and running, in a standard shoe, with and without the
Figure 2(abstract P22) Final orthotic and cross section of arch
geometry.
P22
Design, development and biomechanical evaluation of a prefabricated
anti pronation foot orthosis
Rachel Majumdar, Philip Laxton, Anna Thuesen, Christopher Nester*,
Barry Richards
Centre for Health Sciences Research, University of Salford, Salford, M6 6PU, UK
Background: Custom made foot orthoses remain the ‘gold standard’
because the orthotic geometry is tailored to each patient’s foot. However,
due to their reduced cost, in some contexts there has been an increasing
Figure 1(abstract P22) Final orthotic and cross section of arch
geometry.
Figure 3(abstract P22) Rearfoot inversion(+ve°) and eversion (-ve°)
during walking and running with and without the orthotic. 0° = relaxed
standing.
Figure 4(abstract P22) Rearfoot inversion(+ve°) and eversion (-ve°)
during walking and running with and without the orthotic. 0° = relaxed
standing.
orthosis. Marker triads were attached to the heel via a shoe aperture, and
to the leg.
Results: The orthotic is illustrated in Figure 1 & 2. Maximum rearfoot
eversion was reduced (Figure 3 and 4) in both walking (reduced by 3.4°,
SD3.5°) and running (by 2.2°, SD2.8°)(p<0.001). The walking reduction is
larger than reported by Mills (2.12°) [5] following meta analysis of the
literature, but like other reports the orthotic effect was highly person
specific.
Conclusion: The project produced a foot orthosis with evidence of: its
design and development process; its material properties compared to
existing orthotic materials; its effect on foot pronation.
Acknowledgements: This work was funded under the UK Government
“Knowledge Transfer Partnership” scheme, supporting transfer of
knowledge from Universities to industry.
References
1. Murley GS, Landorf KB, Menz HB: Do foot orthoses change lower limb
muscle activity in flat-arched feet towards a pattern observed in normalarched feet? Clin Biomech 2010, 25:728-36.
2. Baldassin V, Gomes CR, Beraldo PS: Effectiveness of prefabricated and
customized foot orthoses made from low-cost foam for noncomplicated
plantar fasciitis: a randomized controlled trial. Arch Phys Med Rehabil
2009, 90:701-706.
3. Redmond AC, Landorf KB, Keenan AM: Contoured, prefabricated foot
orthoses demonstrate comparable mechanical properties to contoured,
customised foot orthoses: a plantar pressure study. J Foot Ankle Res 2009,
16:2-20.
4. Landorf KB, Keenan AM, Herbert RD: Effectiveness of foot orthoses to
treat plantar fasciitis: a randomized trial. Arch Intern Med 2006,
166:1305-1310.
5. Mills K, Blanch P, Chapman AR, McPoil TG, Vicenzino B: Foot orthoses and
gait: a systematic review and meta-analysis of literature pertaining to
potential mechanisms. Br J Sports Med 2010, 44:1035-1046.
P23
Indicators for the prescription of foot and ankle orthoses for children
with Charcot-Marie-Tooth disease
Grant Scheffers1*, Claire Hiller1, Kathryn Refshauge1, Joshua Burns1,2
1
Faculty of Health Sciences, The University of Sydney, NSW, Australia;
2
Institute for Neuroscience and Muscle Research, Children’s Hospital at
Westmead, Sydney, Australia
Background: Charcot-Marie-Tooth disease (CMT) is the most common
inherited peripheral neuropathy and is associated with foot deformity,
gait abnormalities and functional impairment. Orthoses are often
prescribed for children with CMT, yet the indication and type of
prescription is usually based on clinical judgement due to the lack of
high quality research in this field. Therefore, the aims of this paper were
to review the indications of commonly prescribed foot and ankle
Page 50 of 56
orthoses, and formulate a clinical algorithm for the optimal prescription
of foot and ankle orthoses for children with CMT.
Materials and methods: We searched MEDLINE (from January 1966),
EMBASE (from January 1980), CINAHL (from January 1982), AMED (from
January 1985), Cochrane Neuromuscular Disease Group Specialized
Register, and reference lists of articles.
Results: Table 1 shows a clinical algorithm for prescribing foot and ankle
orthoses for children with CMT. In general, in-shoe orthoses are indicated
for affected children with pes cavus deformity, foot pain and/or mild
balance impairments. Ankle-foot orthoses are indicated for children with
pes cavus, foot drop, foot and ankle muscle weakness and/or ankle
equinus, and moderate-severe balance impairments and/or difficulty
walking (self-reported clumsy gait, frequent trips/falls) and gait
abnormalities (slower speed, shorter step length, wider base of support).
Conclusions: A clinical algorithm is proposed to guide the prescription of
orthoses for children with CMT. Further research is required to determine
the efficacy of different foot and ankle orthoses, and the predictive ability
of the proposed clinical algorithm to improve foot deformity, gait
abnormalities and disability in childhood CMT.
P24
Effect of cognitive task on postural control of the patients with chronic
ankle sprain
Zeinab Shiravi*, Saeed Talebian, Mohammad Reza Hadian, Gholam Reza Oliaie
Dept. Physiotherapy, Rehabilitation Faculty, Tehran University of Medical
Sciences, Tehran, Iran
Background: Chronic ankle instability can affect activities of daily living
in patients. While many studies have indicated postural control deficits in
these patients [1,2], the effect of a dual task on postural control has not
been examined yet [3].
Materials and methods: Postural stability in CAI patients (n=8) and
healthy subjects (n=10) was measured using the Force Plate. Eight
positions concluded two different stances (double & single) with closed
or opened eyes. All positions concurrently were done with a cognitive
task. Anterior/posterior (Rfa) and medial/lateral (Rsw) mean sway, area
and mean velocity quantified static postural control [4].
Results: Mean sway significantly increased in patients in the anterior/
posterior (single and double leg stance) and medial/lateral (single leg
stance) directions (P<0.05). While performing a dual task anterior/
posterior mean sway decreases within the patients group on the
impaired leg stance (P<0.05). Area significantly increased in patients in
single leg stance but decreased in the bilateral standing positions except
open eyes with cognitive task. Mean velocity significantly decreased
(single leg stance) and increased (double leg stance). No difference is
seen in the healthy subjects.
Conclusion: Postural control deficits were identified in participants with
chronic ankle instability. In view of the fact that a cognitive task resulted
Table 1(abstractP23) Clinical algorithm for prescribing foot and ankle orthoses for children with CMT
Impairments and activity limitations
Orthoses
Pes cavus and foot pain
Foot orthoses
Pes cavus and poor balance
UCBL* orthoses
Pes cavus and poorer balance (not corrected by UCBL* orthoses)
Supramalleolar orthoses
Pes cavus and poorer balance (not corrected by supramalleolar AFOs†)
Foot drop and poor walking
Hinged AFOs†
Posterior leaf spring
AFOs†
Foot drop, poor walking, pes cavus, and poor balance
Hinged AFOs† with PF‡
stops
Global weakness of foot/ankle muscles and poor walking and/or balance (with/without pes cavus and/or foot drop)
Global weakness of foot/ankle muscles and poorer walking and/or balance (not corrected by hemispiral AFOs†, with/
without pes cavus and/or foot drop)
Pes cavus and/or ankle equinus (≥ 0°, not corrected by hinged AFOs† with/without PF‡ stops)
Hemispiral AFOs†
Solid AFOs†
* University of California Biomechanics Laboratory; † ankle-foot orthoses; ‡ plantarflexion.
Solid AFOs†
Page 51 of 56
in decreasing displacement of centre of pressure in patients, this method
may identify as an examination and a plan of treatment for affecting on
ankle stabilizing factors.
References
1. De Noronha M, Refshauge KM, Herbert RD, Kilbreath SL, Hertel J: Do
voluntary strength, proprioception, range of motion, or postural sway
predict occurrence of lateral ankle sprain. J Sport Med 2006, 40:824-8.
2. McKoen PO, Hertel J: Systematic Review of Postural Control and Lateral
Ankle Instability, Part1: Can deficits be detected with instrumented
testing. J Athl Train 2008, 43:293-304.
3. Woollocott M, Shumway-cook A: Attention and the control of posture
and gait: a review of an emerging area of research. Gait posture 2002,
16:1-14.
4. Raymarkers JA, Samson MM, Verhaar HJ: The Assessment of Body Sway
and the Choice of the Stability Parameter(s). Gait Posture 2005,
21:48-58.
P25
Investigation of running foot strike technique on Achilles tendon force
using ultrasound techniques and a Hill-type model
Sarah M Stearne*, Jonas Rubenson, Jacqueline Alderson
The School of Sport Science Exercise and Health, The University of Western
Australia, Perth, WA, 6009, Australia
Background: It is reported that 75% of long distance runners use a
rearfoot strike (RFS) technique. This percentage decreases in faster
runners, where the incidence of midfoot and forefoot strikers (FFS)
increases [1]. It is possible that FFS better utilises the passive-elastic
mechanisms of the lower limb reducing energy cost. Williams et al. [2]
found runners who converted from RFS to FFS during a single training
experienced increased fatigue and delayed onset muscle soreness in the
calf musculature, indicating increased muscle work. This research aims to
investigate the role of the Achilles tendon and triceps surae muscles in
FFS versus RFS running hypothesising that the FFS will have increased
Achilles tendon force.
Materials and methods: Natural FFS (n=9) and RFS (n=9) distance
runners ran on a treadmill at 3ms-1 while muscle fibre length change of
the medial and lateral gastrocnemius and soleus were recorded using
ultrasound and muscle activation via surface electromyography. Individual
contribution of the triceps surae muscles to Achilles tendon force was
determined using a Hill-type model based on muscle activation, the
muscles force-length-velocity relationship (from an individually scaled
musculoskeletal OpenSim model), maximum isometric muscle force and
pennation angle. Achilles tendon and triceps surae individual muscle
forces were recorded while runners performed their natural (fore or
rearfoot) and then converted to their unnatural strike.
Results: Results from one FFS participant are presented below (Figure 1 &
2), additional data is being processed. Preliminary results indicate tendon
force is lower than RFS results in the literature.
Figure 1(abstract P25)
Figure 2(abstract P25)
Conclusions: This research provides insight into the role of the Achilles
tendon during FFS running and sheds light on its’ contribution
to reducing energy cost. It also reveals the altered demand on the
triceps surae muscles which may have implications for technique
recommendations and training requirements.
References
1. Hasegawa H, Yamauchi T, Kraemer WJ: Foot strike patterns of runners at
the 15-km point during an elite-level half marathon. J Strength Cond Res
2007, 3:888-893.
2. Williams D, McClay I, Manal T: Lower extremity mechanics in runners with
a converted forefoot strike pattern. J Appl Biomech 2000, 16:210-218.
P26
Rear-foot kinematics in runners with PFPS during walking, squatting
and uphill running
Jessica Leitch1*, Kathleen Reilly2, Julie Stebbins3, Amy B Zavatsky1
1
Department of Engineering Science, University of Oxford, Oxford, OX1 3PJ,
UK; 2Department of Physiotherapy, Nuffield Orthopaedic Centre, Oxford, OX3
7LD, UK; 3Oxford Gait Laboratory, Nuffield Orthopaedic Centre, Oxford, OX3
7LD, UK
Background: Patellofemoral pain syndrome (PFPS) is the most common
overuse injury in distance runners. A pilot investigation found that
runners with a history of PFPS exhibited increased rear-foot eversion and
reduced rear-foot dorsiflexion compared to uninjured controls during
level treadmill running [1]. The aim of the present study was to
investigate whether these kinematic alterations were also demonstrated
during activities that demanded more dorsiflexion (uphill running and
squatting) and less dorsiflexion (walking) compared to level running.
Materials and methods: Nine female runners with a previous history of
PFPS and ten female controls participated in the study. Spherical
reflective markers (9-mm) were attached to anatomical landmarks of both
lower limbs [2]. A 12-camera Vicon MX System (Vicon Motion Systems,
Oxford, UK) was used to collect 3-D spatial data at 200 Hz as the subject
performed (i) five over-ground walking strides (self-selected speed),
(ii) five squats and (iii) five uphill running strides on a treadmill (speed =
2.96 ms-1, incline = 10o). Rear-foot joint angles were calculated using the
Oxford Foot Model [2]. The five trials for each activity and each subject
were normalised to the stance (squat) period using cubic spline
interpolation. Discrete kinematic parameters (peak rear-foot dorsiflexion,
dorsiflexion excursion, peak rear-foot eversion) were identified for each of
the five trials of each subject. The variables were compared between
groups using one-tailed t-tests with an alpha level set at 0.05.
Results: Subjects with a history of PFPS demonstrated significantly less
dorsiflexion (peak) during walking and squatting compared to uninjured
controls (Table 1). Dorsiflexion excursion was significantly lower and rearfoot eversion significantly higher in subjects with a history of PFPS
compared to uninjured controls during uphill running.
Page 52 of 56
Table 1(abstractP26) Kinematic parameters during walking, running and squatting for subjects with a history of PFPS
(P) and uninjured controls (N). * Indicates a statistically significant difference (p < 0.05)
Walk
Uphill Run
Squat
Angle (o)
N
P
p-value
N
P
p-value
N
P
p-value
Peak dorsiflexion
11.2 (3.2)
7.9 (2.8)
0.01*
18.9 (7.2)
15.9 (2.5)
0.13
25.0 (8.2)
19.0 (3.3)
0.03*
Dorsiflexion excursion
Peak eversion
17.0 (2.5)
5.8 (6.2)
15.1 (2.8)
9.5 (3.3)
0.06
0.07
17.5 (3.8)
7.1 (7.5)
14.0 (2.3)
12.8 (3.1)
0.04*
0.03*
19.5 (8.8)
6.5 (10.8)
17.0 (2.5)
10.1 (3.2)
0.21
0.18
Conclusion: The kinematic alterations that had been observed in subjects
with a history of PFPS during level running [1] were also apparent during
walking, uphill running and squatting. Further investigations to understand
the relationship between rear-foot joint motion and patellofemoral joint
kinematics are required.
References
1. Leitch J, Reilly K, Stebbins J, Zavatsky AB: Lower-limb and foot kinematics
in distance runners with patellofemoral pain syndrome. Proceedings of
the 2nd Patellofemoral Pain Syndrome International Research Retreat: August
2011; Ghent,Belgium.
2. Stebbins J, Harrington M, Thompson N, Zavatsky AB, Theologis T:
P27
Asessment of ageing effect on plantar tissue stiffness
Jee-Chin Teoh*, Wen-Ming Chen, Taeyong Lee
Division of Bioengineering, National University of Singapore, Singapore
Background: Foot abnormality has become a public health concern. Early
detection of pathological soft tissue is hence an important preventive
measure, especially to the elderly who generally have a higher risk of foot
pathology (i.e. ulceration) [1]. Accumulated changes over time diminish the
mechanical properties of plantar soft tissue, causing easy breakdown of
tissue and instability of foot during walking. Non invasive in-vivo
assessment on plantar soft tissue mechanical responses is hence needed.
This is to identify abnormal soft tissue such that early precaution measures
can be taken to avoid foot pathology that requires long healing period.
The purpose of this study is to assess ageing effect on plantar tissue using
an improved version of instrumented in vivo tissue tester [2]. It also aims
to provide a useful parameter to identify tissue with high ulceration risk.
This is done by varying metatarsophalangeal (MTP) joint configurations
and imposing large tissue deformation to the soft tissue.
Methods: 10 young (20-30 years) and 10 old subjects (60-70 years)
participated. During the testing, the indentor tip probed the metatarsal
head (MTH) pad tissue at 3 different dorsiflexion angles of 0°, 20°, 40° as
average MTP dorsiflexion was 25°-47° during walking[3]. Maximum tissue
deformation was set at 5.6mm (close to literature data). [4] Experiment was
repeated on 1 st hallux and heel. Tissue stiffness obtained from tissue
response curve was compared (Figure 1).
Results: As MTP dorflexion increased, old subjects had a steeper increase
in stiffness value as compared to the young. Old subjects also showed
significantly higher tissue stiffness in 2nd MTH and heel region.
Conclusion: Notably, aging resulted in stiffer tissue property. Ageing
effect was the most prominent as the MTP dorsiflexion was maximum.
This critical scenario was of utter importance as it had highest ulceration
risk. Previous work had failed to consider MTP dorsiflexion and large
tissue deformation leading to a less critical and less useful stiffness
measurements. This study successfully demonstrated the positive
Figure 1(abstract P27) Comparison of soft tissue stiffness between young and old subjects.
relationship aging and soft tissue stiffness in a realistic manner by better
replicating actual gait condition. It also provided a more useful stiffness
values in identification of potentially abnormal soft tissue.
References
1. Nelzen O, Bergqvist D, Lindhagen A: Venous and non-venous leg ulcers:
clinical history and appearance in a population study. Brit J Surg 1994,
91:182-187.
2. Chen WM, et al: An instrumented tissue tester for measuring soft tissue
property under the metatarsal heads in relation to metatarsophalangeal
joint angle. J Biomech 2011, 44:1801-1804.
3. Griffin NL, Richmond BG: Joint Orientation and function in great ape and
human proximal pedal phalanges. Am J Phys Anthropol 2010, 141:116-123.
4. Cavanagh PR: Plantar soft tissue thickness during ground contact in
walking. J Biomech 1999, 32:623-628.
P28
Shoes that restrict metatarsophalangeal dorsiflexion cause proximal
joint compensations
Dominic Thewlis1,2*, Gunther Paul3, Chris Bishop1
1
Australia, 5000, Australia; 2Sansom Institute for Health Research, University of
South Australia, Adelaide, South Australia, 5000, Australia; 3Mawson Intitute,
University of South Australia, Adelaide, South Australia, 5041, Australia
Study aim: To describe barefoot, shod and in-shoe kinematics during
stance phase of walking gait in a normal arched adult population.
Materials and methods: An equal sample of males and females (n = 24)
was recruited. In order to quantify the effect of footwear independent of
technical design features, an ASICS shoe (Onitsuka Tiger-Mexico 66, Japan)
was used in this study. Markers were applied to three conditions; barefoot,
shod, and in-shoe. The calibration markers were used to define static pose.
The order of testing was randomised. Participants completed five trials in
each condition. Kinematic data were captured using a 12 camera VICON
MX40 motion capture system at 100 Hz and processed in Visual3D.
A previously developed model was used to describe joint angles [1].
A univariate two-way ANOVA was used to identify any differences between
the pairs of conditions. Post-hoc Sheffé tests were used to further
interrogate the data for differences.
Results: At peak hallux dorsiflexion (Figure 1), during propulsion, the
metatarsophalangeal joint (MPTJ) was significantly more dorsiflexed in
the barefoot condition compared to the shod condition (p = 0.004).
At the same gait event, the tibiocalcaneal joint (TCJ) was significantly
more plantarflexed than both the shod and in-shoe conditions (p <
Figure 1(abstract P28) Joint angles (degrees) at peak hallux dorsiflexion.
Page 53 of 56
0.001), and the tarsometatarsal joint (TMTJ) was significantly less
dorsiflexed in the barefoot condition compared to the shod and in-shoe
conditions (p < 0.001).
Conclusions: The findings of the current study demonstrate that
footwear has significant effects on sagittal plane MPTJ joint dorsiflexion
at peak hallux dorsiflexion, which results in compensations at proximal
foot joints.
Acknowledgements: ASICS Oceania provided the footwear for the study.
Reference
1. Bishop C, et al: The development of a multi-segment kinematic model of
footwear. Footwear Science 2011, 3:S13-S15.
P29
Multi-segment foot motion during single limb toe raises in healthy
individuals
Kirsten Tulchin1,2*, Wilshaw R Stevens Jr1, Kunal Singhal2, Young-Hoo Kwon2
1
Movement Science Laboratory, Texas Scottish Rite Hospital for Children,
Dallas, Texas, 75219, USA; 2Department of Kinesiology, Texas Woman’s
University, Denton, Texas, 76207, USA
Background: The standing toe raise, or heel rise, requires ankle
plantarflexor strength, and is often used to assess foot and ankle muscle
function. There is limited research on the mechanics within the foot during
this task. Houck et al., [1] found that hindfoot eversion/inversion was
significantly different than controls during a bilateral toe raise task in
patients with posterior tibialis tendon dysfunction. They concluded,
however, that most differences in foot kinematics in this patient population
occurred as an offset rather than a change in pattern of motion. However
the kinematic patterns of motion during a unilateral toe raise task remain
unknown. The purpose of this study was to describe the multi-segment foot
kinematics during a single legged toe raise in adults without a history of
foot disease.
Materials and methods: Eighteen adults (12 males/6 females) with a
mean age of 27.5 ± 5.8 yrs (range: 20.0-37.4) were instructed to perform
20 unilateral single limb toe raises, while maintaining a straight knee.
Subjects were required to balance during the task on their own. The full
body Plug-in-Gait model (VICON, Centennial, CO, USA) was used to assess
lower extremity kinematics/kinetics, and the TSRHC kinematic multisegment foot model [2] was applied bilaterally. Custom-written MATLAB
code was used to automate the identification of each toe raise based on
the position, velocity and acceleration of the heel marker on the stance
limb. A single side was chosen from each subject, with a minimum of
15 completed toe raises selected for analysis for each individual. Maximal
vertical excursion of the heel was determined by the displacement of the
posterior calcaneus marker and was normalized relative to foot length
(heel marker to metatarsal heads during the static trial.) Descriptive
statistics were derived for hindfoot motion and forefoot motion (triplanar)
and normalized heel excursion.
Results: Normalized heel excursion was found to be correlated to sagittal
plane hindfoot and forefoot range of motion (r 2 =0.59 and r 2 =0.49,
respectively) and peak ankle power generation (r 2 =0.63). There were
strong correlations in the timing of peak heel excursion and the
occurrence of peak hindfoot plantarflexion (r 2 =0.89), peak forefoot
plantarflexion (r2=0.63) and peak ankle power generation (r2=0.59).
There was slight hindfoot varus and forefoot eversion noted during the
heel rise, however the pattern of motion in the coronal plane was not
consistent across subjects or trials. Those that exhibited a hindfoot varus
pattern (VAR group) had slightly higher coronal hindfoot range of motion
than those that did not (8.6° vs. 5.1°, p<0.001) while those that did not
have a varus pattern (NON-Var group) exhibited more hindfoot internal
rotation (16.6° vs. 8.6°, p<0.001). Most differences between groups
occurred at the hindfoot, with minimal differences at the forefoot. There
was no significant difference in normalized heel excursion between the
two groups (p=0.241). Despite instructions to keep the knee straight, mean
knee flexion was approximately 13.4 ± 5.5° across all subjects, with a total
range of motion of slightly over 7°.
Conclusions: Kinematic patterns of motion within the foot during a
single limb toe raises were variable among healthy young adults. Most
significant differences across patterns occurred within the hindfoot, with
minimal changes noted at the forefoot, which suggests that proximal
motion at other joints plays a crucial role in multi-segment foot
kinematics. Specifically, the effect of the control and location of the
center of mass relative to the foot warrants further investigation.
References
1. Houck J, Neville C, Tome J, Flemister A: Foot kinematics during a bilateral
heel rise test in participants with stage II posterior tibialis tendon
dysfunction. J Orthop Sports Phys Ther 2009, 39:593-603.
2. Tulchin K, Orendurff M, Adolfsen S, Karol L: Effect of walking speed on
multi-segment foot kinematics in adults”. J Appl Biomech 2009, 25:377-386.
P30
Abstract withdrawn
Abstract withdrawn:
P31
Children’s functional performance barefoot and in sports shoes
Caleb Wegener1*, Andrew Greene1, Renee Millar1, Joshua Burns2,
Adrienne E Hunt1, Benedicte Vanwanseele3, Richard M Smith1
1
Discipline of Exercise and Sports Science, Faculty of Health Sciences, The
University of Sydney, NSW, 1825, Australia; 2Faculty of Health Sciences, The
University of Sydney/ Institute for Neuroscience and Muscle Research, The
Children’s Hospital at Westmead, Sydney, NSW, 2145, Australia; 3Research Centre
for Exercise and Health, KULeuven, Leuven, Belgium / Chair Health Innovation
and Technology, Fontys University of Applied Sciences, Eindhoven, Netherlands
Background: Shoes have a considerable impact on children’s walking
and running biomechanics [1]. Given the number of significant changes
shoes make to children’s gait, shoes may also affect children’s ability to
perform functional tasks. This study aimed to determine the effect of
shoes on children’s balance, standing long jump and running agility.
Methods: Nine boys and 10 girls (mean age 10 years (SD1.4)) performed
four activities barefoot and wearing sports shoes (Kanbarra, Asics Oceania
Pty Ltd.) in a randomised order. To allow for a gradual warm up, activities
were undertaken in a predetermined order of: 2x20sec single leg balance
eyes open; 2 x20sec single leg balance eyes closed; 2x standing long
jump; timed running agility (4x10m). These tasks were undertaken as
previously described in the literature [2,3]. The balance tasks were
Page 54 of 56
undertaken on concrete surface, while the standing long jump and agility
were undertaken on carpet. The better of two performances, except
running agility in which only one attempt was undertaken, were selected
for analysis. Significance was assessed with the Wilcoxon Signed rank test
for non-parametric data and a paired samples t-test for parametric data.
Results: Shoes did not significantly alter single leg balance with eyes
open (20sec (0) to 20sec (0); p=1.00) or with eyes closed (12.4sec (7.9) to
14.4sec (7.4); p=0.255). Children jumped further in shoes (1.43m (0.24) to
1.48m (0.23); p=0.033). Running agility did not significantly change in
shoes (12.8sec (1.1) to 12.9sec (1.4); p=0.250).
Conclusions: Shoes improve children’s standing long jump performance.
This is possibly due to increased perception of protection on landing or
improved friction between the outersole and carpet. Alternatively the
splinting effect of shoes could improve force transfer from the calf
musculature to the foot and ground. Sports shoes do not impair static
balance or agility but do improve children’s standing long jump.
References
1. Wegener C, Hunt AE, Vanwanseele B, Burns J, Smith RM: Effect of
children’s shoes on gait:a systematic review and meta-analysis. J Foot
Ankle Res 2011, 4:3.
2. Ortega FB, Artero EG, Ruiz JR, Vicente-Rodriguez G, Bergman P,
Hagströmer M, Ottevaere C, Nagy E, Konsta O, Rey-López JP, Polito A,
Dietrich S, Plada M, Béghin L, Manios Y, Sjöström M, Castillo MJ: Reliability
of health-related physical fitness tests in European adolescents. The
HELENA Study. Int J Obes(lond) 2008, 32:S49-S57.
3. Humphriss R, Hall A, May M, Macleod J: Balance ability of 7 and 10 year
old children in the population: Results from a large UK birth cohort
study. Int J Pediatr Otorhinolaryngol 2011, 75:106-113.
P32
Plantar pressure distribution during gait and running in subjects with
chronic ankle instability
Roel De Ridder*, Tine Willems, Philip Roosen
Departement of Rehabilitation Sciences and Physiotherapy, Ghent University,
Ghent, 9000, Belgium
Background: Lateral ankle sprains are one of the most common injuries
in athletes. Up to 32% of subjects with an ankle sprain develop residual
symptoms labeled as chronic ankle instability (CAI), with a significant
impact on the quality of life. In spite of many research the underlying
mechanisms for CAI remain unclear. The foot roll-off pattern of subjects
with CAI is one of the factors which may play an important role in
recurring ankle sprains and the presence of ‘giving way’ episodes. A more
lateral pressure distribution has been suggested in subject with CAI,
resulting in higher risk for developing an ankle sprain, but research is
limited [1]. Especially in dynamic conditions research is needed. This
study includes gait as well as a running condition and investigates
plantar pressure distribution on five distinct moments and during 4
phases relative to total foot contact as shown in figure 1 [2].
Materials and methods: Plantar pressure distribution of 93 subjects (42
subjects with CAI, 21 copers and 29 healthy subjects) was registered during
barefoot walking and running. Data was collected on a 20m long runway
with a Footscan® pressure plate imbedded on top of a forceplate (AMTI).
Medio-lateral ratios were calculated for the five distinct moments and
during the four phases of the stance phase. Temporal data, peak pressure,
mean force and impulse for the different zones of the foot were also
calculated.
Results: Statistical analysis did not show significant differences between
the groups for any of the tested parameters nor for the medio-lateral
ratios at the different moments and during the phases.
Conclusions: This study does not confirm the results of previous studies
suggesting a more lateral pressure distribution. Further research is needed.
References
1. Morisson K, Hudson D, Davis I, et al: Plantar pressure during running in
subjects with chronic ankle instability. Foot Ankle Int 2010, 31:994-1000.
2. Willems T, Witvrouw E, Delbaere K, et al: Relationship between gait
biomechanics and inversion sprains: a prospective study of risk factors.
Gait Posture 2005, 21:379-38.
Page 55 of 56
Figure 1(abstract P32) Five distinct moments and phases relative to total foot contact [2].
P33
The effect of fatigue on plantar pressure distribution during running in
view of running injuries
Tine M Willems*, Roel De Ridder, Philip Roosen
Department of Rehabilitation Sciences and Physiotherapy, Ghent University,
Ghent, Belgium, 9000
Background: Several risk factors for the development of running injuries
have been identified, however, the etiology is still not completely clear
[1]. A number of prospective studies have identified gait-related risk
factors for lower leg overuse injuries [2-6]. On the other hand, running
injuries only develop by overloading the lower extremity. Fatigue can
therefore be hypothesized to be a primary contributing factor. However,
in determining injury etiology the relationship between the injury, the
gait-related risk factors and overloading by fatigue is a complex model
and the amount of contribution of each factor is difficult to assess. It
Figure 1(abstract P33) Significantly changed impulse, peak force and mean force for the different zones.
might therefore be interesting to check 1) the interaction between
fatigue and the roll-off pattern during running and 2)if fatigue generates
specific gait-related risk factors for running injuries.
Materials and methods: Prior to and after a 20 km run, force
distribution underneath the feet of 52 participants was registered using
Footscan® pressure plates while the participants ran shod at a constant
self-selected pace. Peak force, mean force and impulse were registered
underneath different zones of the foot. In addition, temporal data were
derived and a medio-lateral force ratio was calculated during the roll-off.
Results: After the run, increases in the loading of the forefoot, midfoot
and medial heel were noted and decreases in loading of the lateral toes.
Significant differences are presented in Figure 1. In the forefoot push off
phase a more lateral pressure distribution was observed.
Conclusions: Several of the significantly increased variables have been
identified as risk factors for running injuries as stress fractures, patellafemoral pain syndrome and exercise-related lower leg pain. The results of
this study demonstrated plantar pressure alterations after long-distance
running which could give additional information related to several
running injuries.
References
1. Van Gent RN, Siem D, van Middelkoop M, et al: Incidence and
determinants of lower extremity running injuries in long distance
runners: a systematic review. Br J Sports Med 2007, 41:469-80.
Page 56 of 56
2.
3.
4.
5.
6.
Ghani Zadeh Hesar N, Van Ginckel A, Cools A, et al: A prospective study
on gait-related intrinsic risk factors for lower leg overuse injuries. Br J
Sports Med 2009, 43:1057-1061.
Thijs Y, De Clercq D, Roosen P, et al: Gait-related intrinsic risk factors for
patellofemoral pain in novice recreational runners. Br J Sports Med 2008,
42:466-471.
Thijs Y, Van Tiggelen D, Roosen P, et al: A prospective study on gaitrelated intrinsic risk factors for patellofemoral pain. Clin J Sport Med 2007,
17:437-445.
Van Ginckel A, Thijs Y, Hesar NG, et al: Intrinsic gait-related risk factors for
Achilles tendinopathy in novice runners: a prospective study. Gait
Posture 2009, 29:387-391.
Willems TM, De Clercq D, Delbaere K, et al: A prospective study of gait
related risk factors for exercise-related lower leg pain. Gait Posture 2006,
23:91-98.
Cite abstracts in this supplement using the relevant abstract number,
e.g.: Willems et al.: The effect of fatigue on plantar pressure distribution
during running in view of running injuries. Journal of Foot and Ankle
Research 2012, 5(Suppl 1):P33

PDF (all abstracts) - Journal of Foot and Ankle Research

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