Hand Biomechanics

Hand Biomechanics
Li-Chieh Kuo,, Ph.D
Department of Occupational Therapy,
Institute of Allied Health Science,
Motion Analysis Group, Hand Research Group,
National Cheng Kung University, Tainan, TAIWAN
April, 2011
1
What is Biomechanics?
• Application of the laws of mechanics to biological systems
1
Why Focus on the Hand?
3
The Role of the Hand (1)
• To perform fine manipulative movements
– Fingers and thumb to operate
– Intrinsic muscles
– Skillful activities
• To grasp and release objects and tools
– Thumb is placed opposite to the fingers
4
2
The Role of the Hand (2)
• As a sense organ to explore the environment
and to recognize objects
–
–
–
–
Palm
P
l and
d fi
fingertip
ti  richly
i hl supplied
li d with
ith receptors
t
A large area of somatosensory cortex
Feedback
Stereognosis
• To use in the communication
and expression of emotion
5
The Role of the Hand (3)
• Cortical homunculus
6
3
The Impact of Upper Limb Impairment
• Differences between upper
limb and lower limb
• Loss of thumb is equivalence
q
to a 40% - 50% permanent of
the hand
7
Something behind Clinical Judgments
8
4
LE impairments vs. UE impairments
http://www.orthopaedie.uni-hd.de/
LE impairments vs. UE impairments
• Bilateral coordination
• Tools prehension
5
LE impairments vs. UE impairments
LE impairments vs. UE impairments
• Myoelectric prosthesis
6
LE impairments vs. UE impairments
Advances in upper limb
technology
•
•
•
•
•
Treatment protocol
Prosthetic interface
Materials
Microprocessor technology
Terminal devices
http://www.ottobockus.com/
7
iLimb (Touch EMAS Limited, Edinburgh, UK.)
http://www.technovelgy.com/graphics/content07/iLimb-luke.jpg
8
Anatomy
Biomechanics
17
Anatomy of Upper Extremity (1)
• Bones
18
9
Hand Anatomical Structures
• Bones
– Metacarpal bones, phalanges, carpal bones
• Joints
– Carpometacarpal (CMC) joint
– Metacarpophalangeal (MCP) joint
– Interphalangeal (IP) joint
• A strong palmar ligament
• Collateral
C
ligaments
• Movements
19
– Flexion, extension
– Abduction, adduction
Hand Anatomical Structures
• Carpometacarpal (CMC) joint
–
–
–
–
Thumb
1st metacarpal & trapezium
Synovial saddle joint
Lateral, anterior & posterior ligaments
(Cooney et al., 1981)
20
10
Hand Anatomical Structures
5 Annular Pulleys & 3 Cruciform Ligaments
Hand Anatomical Structures
Arches and Rays of the Hand
• 3 arches
• 5 digital rays
– Th
The llongitudinal
it di l arch
h
– The distal transverse arch
– The proximal transverse arch
11
Hand Biomechanics Studies
23
Bony Mechanisms
24
12
Bony Mechanisms
• Bony morphology
• Precise opposition of articular surface
25
Ligamentous Mechanisms
• Wrist ligaments
–
–
–
–
Restrict joint motion
A
Appose
joint
j i t surface
f
Induce bony displacement
Transmit loads
26
13
Ligamentous Mechanisms
• Hand ligaments
– Balanced forces of intrinsic and extrinsic musculature
– Stability and control of the hand
• Roles of ligaments in the maintenance of kinematics of the
trapeziometacarpal joint (Imaeda, 1994; 1996; Uchiyama, 1999)
27
Ligamentous Mechanisms
• Hand
– Trigger digits
• A1 Pulley Mechanics
28
14
Muscular--Tendinous Mechanisms
Muscular
• Excursion
• Gliding resistance
Z axis
Y axis
29
The measurement system
actuator and linear
potentiometer
Load transducer
(F2)
Load transducer
(F1)
EPB
5º
APL
F2-F1 = gliding resistance of EPB tendon within retinaculum ligament
30
15
A Functional Hand
Kinematics
Sensibility
Coordination
Kinetics
3
1
Quantitative Assessment of
Motions Impairment in the
Hand
The Concept of 2D & 3D Workspace & Goniometry
32
J Hand Surg
Surg,, 21B(5):604
21B(5):604--608, 1996
J Hand Surg, 23(B):53-56, 1998
J Hand Surg, 25B:195-199, 2000
P I Mech Eng–H: J Eng Med, 216:257-263, 2002
16
Measurement of Hand Movements
• Traditional linear & goniometric measures
– ROM, TAM-TPM
– AMA Guide
33
Measurement of Impaired Finger Motion
• Maximal Fingertip Motion Area (Chiu, 1995)
– Direct measurement of 2-D working area of a fingertip
– Obtained actual working space
– Adopt five extreme postures
 Various combinations of
contraction and relaxation
of the finger motors
34
17
Motion Analysis for Injured Finger
HYC
Maximal Fingertip Motion Area
Crush Injured Patient
Normal Subject
10
10
5
5
A
D
0
cm
0
-5
cm
-5
-10
-10
-15
-15
-20
-15
-10
-5
0
5
-20
10
-15
-10
-5
0
5
10
15
cm
10
5
cm
0
1st month
-5
-10
-10
-5
0
2nd month
5
10
15
36
cm
18
Application in PrePre- & PostPost-Intervention
Assessment in Trigger Digits
37
Thumb Kinematical Model
• Thumb Model
J Biomech, 35:1499-1506, 2002
J Biomech, 36:937-942, 2003
Clin Biomech, 18:558-563, 2003
PIMEH: J Eng Med, 218:143-149, 2004
J Orthop Res
Res, 22:600-606,
22:600-606 2005
– Feasibility test
– 3D kinematical model
A
B
38
19
Thumb Kinematical Model

Trapeziometacarpal model
• in vitro study
• in vivo study
39
Functional Workspace of Hand
• Observation of prehensile performances
• A well-coordinated thumb-finger relationship
• Few functional tasks in daily living require extreme
movements of fingers and thumb
• “Functional workspace (FW)” concept
40
20
Functional Workspace of Hand
41
KY Lai, TH Yang, KC Chen, LC Kuo
BIOMECHANICS OF HAND
DURING PIANO PLAYING
• Pianists are an occupational or leisure group
• 40-80% of pianists have musculoskeletal problems
• Statistical comparison of kinematic & kinetic
differences attributed to hand span while playing
two technical music scores
42
21
Methods
Small hand span
(10 subjects)
Large hand span
(10 subjects)
20
subjects
43
Results
Ratio of maximal digitdigit-to
to--digit abduction angle
Chord
Octave
44
22
Results
Ratio of maximal digitdigit-to
to--digit abduction angle
Rmax.abd_
Mean ((SD))
Octave
Z
P
Large hand span
(n=10)
Small hand span
(n=10)
(2-tailed Sig.)
R_thumb (%)
92.79 (15.54)
130.13 (15.45)
-3.55
0.000**
R_index finger (%)
70.67 (23.58)
106.47 (25.71)
-2.65
0.008**
R_ring finger (%)
83.27 (30.64)
106.82 (25.01)
-1.97
0.049*
R_little finger (%)
97.13 (17.60)
105.60 (8.07)
-1.89
0.059
L_thumb (%)
85.04 (13.16)
118.61 (15.81)
-3.33
0.001**
L_index finger (%)
72.86 (20.42)
96.36 (24.05)
-2.12
0.034*
L_ring finger (%)
66.29 (22.06)
100.87 (27.49)
-2.65
0.008**
L_little finger (%)
81.64 (20.77)
105.76 (12.18)
-2.42
0.016*
* P < .05
** P < .01
45
Results
Fingertip force between large & small hand span
Fingertip force_chord
Large hand span
Small hand span
1.6
1.5
Force (N)
14
1.4
1.3
1.2
1.1
1.0
0.9
0.8
R1
R2
R3
R4
R5
L1
L2
L3
L4
L5
Fingertip (Chord)
R_thumb
R
thumb (N)
R_index finger (N)
R_middle finger (N)
R_ring finger (N)
R_little finger (N)
L_thumb (N)
L_index finger (N)
L_middle finger (N)
L_ring finger (N)
L_little finger (N)
平均值(標準差)
Z
手距大組
(n=10)
手距小組
(n=10)
11.12
12 (0.37)
(0 37)
1.04 (0.37)
1.06 (0.38)
0.84 (0.21)
1.05 (0.28)
1.27 (0.37)
1.33 (0.45)
1.23 (0.30)
1.16 (0.28)
1.04 (0.21)
11.19
19 (0.46)
(0 46)
0.92 (0.26)
1.10 (0.45)
0.93 (0.32)
1.28 (0.66)
1.59 (0.53)
1.51 (0.55)
1.49 (0.53)
1.37 (0.43)
1.38 (0.37)
P
(2-tailed Sig.)
-00.30
30
-0.68
-0.08
-0.30
-0.38
-1.51
-0.98
-1.06
-1.13
-2.12
00.762
762
0.496
0.940
0.762
0.705
0.131
0.326
0.290
0.257
0.034*
2.6
Large hand span
Small hand span
2.5
Fingertip force_octave
Force (N)
2.4
2.3
平均值(標準差)
手距大組
(n=10)
手距小組
(n=10)
Z
P
(2-tailed Sig.)
2.2
R_thumb (N)
2.49 (1.15)
2.40 (0.97)
-0.15
0.88
2.1
R_little finger (N)
2.44 (0.95)
2.53 (1.12)
0.00
1.00
2.0
L_thumb (N)
2.27 (0.93)
2.29 (0.91)
0.00
1.00
1.9
L_little finger (N)
1.91 (0.62)
2.15 (0.82)
-0.68
0.496
R1
R5
L1
Fingertip (Ocatve)
L5
* P < .05
46
23
HAND KINEMATICS DURING
BASEBALL PITCHING
王苓華
Gross motor skill
羅國城
郭立杰
石昇文
Fine motor skill
Baseball pitching
Enhance
Performances
Prevent
Injuries
Hand Kinematics of Baseball
Pitching
Fast
Slider
Curve
24
Hand Kinematics of Baseball Pitching
Ball release
Ball releas
60
60
extension(+)/flexion(-)
abduction(+)/adduction(-)
50
Wrist joint angle
e(
30
20
10
0
-10
0
10
20
30
40
50
60
70
80
90
40
30
30
20
10
20
10
0
0
-10
-10
-20
100
0
10
20
30
40
50
extension(+)/flexion(-)
abduction(+)/adduction(-)
50
40
60
70
80
90
-20
100
0
10
20
30
40
50
60
70
80
90
100
Cycle%
Cycle%
Cycle%
Joint angle in initial phase (degree)
Joint angle in initial phase
Movement
Fast
(n=19)
Slider
(n=14)
Curveball
(n=11)
p
Wrist
flex/ext
25.5(8.5)
31.2 (8.3)
14.4(8.5)
0.34
abd/add
10.3 (6.1)
2.4 (3.9)
0.7(1.9)
0.004
Comparison
FA>SL
FA>CU
Hand Kinematics of Baseball Pitching
Ball release
Ball release
40
50
Fastball
Slider@2
Curveball@3
E
E@2
E@3
40
30
Joint angle(
J
-20
Jo
oint angle(
Wrist joint angle
e(
40
Joint angle(
50
Ball relea
60
abduction(+)/adduction(-)
extension(+)/flexion(-)
30
20
20
10
10
0
10
20
30
40
50
60
70
80
90
100
0
10
20
Movement
Index finger
mp flex/ext(+)
mp abd/add(+)
pip flexion
Middle finger
mp flex/ext(+)
mp Abd/add(+)
pip flexion
*p<.05
30
40
50
60
70
80
90
100
Cycle%
Cycle%
Joint angle in ball release Joint angle in ball release (degree)
(degree)
Fast
Slider
Curveball ‐6.6(17.7)
3.4(18.1)
26.8(6.2)
‐24.2(14.8)
6.7(8.4)
32.3(3.1)
‐9.1(5.9)
27.4(18.7)
19.6(8.1)
‐5.4(13.2)
‐3.3(12.6)
27.2(5.3)
‐23.3(12.3) ‐23.2(14.5)
‐10.3(8.3) 9.9(11.73)
34.0(3.8)
36.2(5.0)
Comparison
FA>SL, SL>CU
CU > FA& SL
SL>FA SL>CU FA>CU
FA> SL&CU
CU> FA&SL
SL>FA CU>SL, CU>FA
25
手部力學模型及功能性評估之建立
Kinetic Model Development
Causes
• Repeatedly performing hand and thumb motions
– grasping, pinching, squeezing, or wringing may lead to
the inflammation of tenosynovitis.
– iPod Finger, BlackBerry Thumb, Wiiitis
26
Revolution !!!
Clinical power measurement
Grasp meter & Pinch meter
53
Kinetic Model Development

Apparatus design

Jar opening device
Y
Unit：mm
[Pa]
B
M
F
×
α
40
Mm, Fm
θ
[Plc]
×
X
C
32
×
A
27
Kinetic Model Development


Hand twisting analysis

Force and Torque contribution
Muscular and joint reaction forces

Role of intrinsic muscle
Results
• Clockwise or
counterclockwise?
• The role of digits?
56
28
Study of Finger Coordination
from Kinetic Perspectives
從力學觀點來探討手指協調模式
A glass simulator recorded the applied loads of the thumb and digits
NORMAL
57
T‐IML
Force distribution pattern
• Fy and Fz showed different patterns.
thumb
0.5
0.4
0.3
0.2
0.1
0
little
x
z
index
ring
x
middle
z
N
Normal_Fy
l F
Central axis
Normal_Fz
Thumb
Index
Middle
Ring
Little
Fy
0.17(.15)
0.27(.13)
0.28(.10)
0.18(.08)
0.10(.05)
Fz
0.51(.01)
0.25(.05)
0.12(.04)
0.07(.02)
0.04(.02)
29
Force distribution pattern in Fz
tz
tz
0.5
0.5
0.4
0.4
0.3
* lz
0.2
*
iz
0.1
0
0.3
*
0.2
lz
iz
0.1
0
Normal
Normal
T‐MRL
rz
T‐IRL
mz
*
*
*
rz
mz
Similar shape among trials, except T‐MRL
tz
tz
0.5
0.5
0.4
0.4
0.3
* lz
0.3
0.2
iz
0.2
lz
0.1
iz
0.1
0
0
Normal
Normal
T‐IMR
T‐IML
rz
mz
*
rz
*
mz
*
SM Hsu, YC Lin, LC Kuo
BIOMECHANICAL ANALYSIS
OF HANDWRITING MOVEMENT
Dynamic tripod grip Lateral tripod grip
Dynamic quadruped grip
Interdigital tripod grip
60
30
Biomechanical analysis of handwriting
• Pen Kinetics
P
B
e
a
D
n
re
-r
s
t
e
k
li
p
f
fo
fo
r
ro
c
r
e
c
c
e
e
Force on the pen
Normal Pen
Force
Axial Pen Force
Custom pen with three pressure sensors and a load cell
on it
61
Functional Sensibility
Assessment
HY Hsu, FC Su, HY Chiu, IM Jou, SJ Shieh, LC Kuo
The eyes of the fingers
(Moberg E, 1966)
62
31
Functional Sensibility Measurement

Apparatus design
Pinch device setup

63
Functional Sensibility Measurement

Functional sensibility test

Functional sensibility parameters
Percentage of maximal p
pinch force
Different controlled conditions
case1
case2
case3
case4
case5
case6
case7
case8
case9
case10
case11
case12
case13
0.8
0.7
0.6
0.5
0.4
0.3
0.2
preop
postop
Test duration=5.4 weeks
Mean
3.0
Force ratio (FPpeak: FLmax)

CTR
0.9
2.5(0..2)
(
)
p=0.007*
2.5
2.0(0.4)
2.0
1.5
1.0
0.5
0.0
preoperation
postoperation
Force ratio before and after carpal tunnel
64release
32
Biofeedback System
JKuo
65
Thanks for your Attention!
66
33