Pes Cavus and Pes Planus - Physical Therapy Journal

Pes Cavus and Pes Planus: Analyses and Treatment
Abby Herzog Franco
PHYS THER. 1987; 67:688-694.
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Pes Cavus and Pes Planus
Analyses and Treatment
ABBY HERZOG FRANCO
The arch of the foot serves as an adaptable, supportive base for the entire body.
This article discusses how the arch of the foot affects the normal biomechanics
of the lower limb. An anatomical overview of the three components of the arch of
the foot is presented, identifying the medial longitudinal arch as the arch mainly
responsible for related structural problems throughout the lower limb. Deviations
in the normal structure of the medial longitudinal arch produce unbalanced,
functionally unstable conditions of the foot such as pes cavus or pes planus.
Specific evaluation criteria for both pes cavus and pes planus are discussed, in
addition to the adverse effects these two disorders have on weight bearing, force
dissipation, and normal gait. Compensatory pronation associated with pes planus
is one of the most common lower extremity disorders seen currently by physical
therapists working in sports medicine, and its causes and related lower limb
disorders are discussed. Most of these structural deformities can be corrected
through the use of various orthotic devices. Specific guidelines are presented for
using both soft and permanent orthoses, which offer the foot increased shock
absorption and proper structural alignment.
Key Words: Foot, Orthotic devices, Physical therapy.
A functional relationship exists between the structure of the arch of the
foot and the biomechanics of the lower
limb. The arch of the foot provides an
elastic, springy connection between the
forefoot and the hindfoot. This relationship ensures that most of the forces incurred during weight bearing can be dissipated before reaching the long bones
of the leg and thigh.
The arch of the foot demonstrates two
extremes of anatomical structural position—the high arch characteristic of pes
cavus and the flat arch characteristic of
pes planus. Although three distinct
arches function to support the foot, the
medial longitudinal arch (MLA) has
been found to be the arch of clinical
significance in both of these disorders.
Problems and malalignments originating specifically with the MLA ultimately
affect the functioning of the muscles and
joints of the ankle, knee, hip, and low
back, all of which depend on the base
of support provided by the MLA.
A strong need exists for physical therapists to understand applied anatomy
and biomechanics of the arch of the foot
Ms. Franco is a student in the physical therapy
program, Florida International University, Tamiami Trail, Miami, FL 33199. She was Head Athletic Trainer, Barnard College of Columbia University, 606 W 120 St, New York, NY 10027, when
this study was conducted. Address correspondence
to 8181 Boca Rio Dr, Boca Raton, FL 33433 (USA).
This article was submitted March 27, 1986; was
with the author for revision three weeks; and was
accepted July 23, 1986. Potential Conflict of Interest; 4.
as it relates to common lower limb disorders. Muscular imbalances, structural
malalignments of joints, compensatory
pronation of the foot, and gait abnormalities often are caused by pes cavus
or pes planus. After a comprehensive
evaluation, the physical therapist can
use various orthotic devices to balance
the foot and restore normal function of
the lower limb.
ANATOMICAL OVERVIEW
The intricate alignment of the bony
structure of the foot, produced by the
tarsal and metatarsal bones and their
corresponding ligaments, results in the
interdependent formation of one transverse and two longitudinal arches. These
supporting arches are designed to absorb
and distribute body weight and to improve locomotion by increasing speed
and agility during gait. The plantar
arches provide both stability and flexibility, meeting the different, complex
requirements of the foot at different
phases of the gait cycle.1-5 The arches
must act as a rigid lever for proper mobility, but they also must be resilient
and flexible for adaptation to different
surfaces.
The design of the arches can be understood by picturing the foot as a twisted
osteoligamentous plate.2 The anterior
edge of the plate (formed by the metatarsal heads), is horizontal and in full
contact with the ground. The posterior
edge of the plate (the posterior calca-
neus), is vertical. The resulting twist
forms the longitudinal and transverse
arches. During weight bearing, the plate
will untwist, flattening the arches
slightly. As the foot is unloaded of
weight, the resilient arches return to
their original shape. The actual mechanism of twisting and untwisting is accomplished through motion at the talocalcaneonavicular, transverse tarsal, and
tarsometatarsal joints that link the
bones of the plantar arches.2
The transverse arch of the forefoot is
located immediately behind the metatarsal heads and can be visualized spanning across the tarsometatarsal joints,
its integrity being maintained by the
wedge-shaped cuneiforms. The middle
cuneiform serves as the keystone of the
transverse arch.6 At the level of the
metatarsal heads, the curvature of the
arch is reduced greatly because the
metatarsal heads are in alignment, parallel to the weight-bearing surface. Also
assisting in holding the base of the arch
together are the tendons of the peroneus
longus muscle, the oblique head of the
adductor hallucis muscle, and the flexor
hallucis brevis muscle.7
The longitudinal arches, both medial
and lateral, are supported by the plantar
ligament arising from the calcaneus and
extending forward to attach to the metatarsals near the heads.8 The longitudinal
arch also is supported by the plantar
aponeurosis, which is the dense fascia
that spans from the calcaneus to the
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PHYSICAL THERAPY
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PRACTICE
alone maintain the arched form of the
foot.11 The MLA, which is the arch of
clinical significance in both pes cavus
and pes planus, will be the arch referred
to in the remainder of this article.
NORMAL WEIGHT BEARING
AND FORCE DISSIPATION
Fig. 1. Supporting structures of the medial longitudinal arch: 1) The tibialis anterior, 2) the
tibialis posterior, 3) the spring ligament, 4) the plantar aponeurosis.
proximal phalanx of each toe.4,9 The
lateral longitudinal arch is formed by
the bony structural relationship between
the calcaneus, cuboid, and metatarsals,
with the cuboid serving as the keystone
of the arch.10 Both the long and short
plantar ligaments restrict motion at the
calcaneocuboid aspect of the transverse
tarsal joint by maintaining the normal
twist between the forefoot and hindfoot.
The integrity of the MLA is preserved
by the bony structure of the foot, strong
ligaments, and active muscles (Fig. 1).
The MLA is composed of five bones,
with the navicular serving as the keystone of the arch.6 The spring ligament,
or the plantar calcaneonavicular ligament, is the main support of the MLA.1
As the spring ligament crosses the transverse tarsal joint (the calcaneocuboid
and talonavicular joints), it restricts
joint motion that contributes to the flattening of the arch. During weight bearing, the spring ligament offers some
elasticity and springiness to the arch.2
Normally, the dorsum of the foot is
domed because of the MLA. The arch
is more prominent in the nonweightbearing position than in the weightbearing position. The MLA is reinforced
further by the tibialis anterior and tibialis posterior muscles, whose tendons
pull the medial border of the foot upward.6 The long flexor muscles, whose
In normal weight bearing, forces are
transmitted through the talus to the medial aspect of the foot, specifically to the
talonavicular part of the transverse tarsal joint, causing pronation of the forefoot. The weight of the body drives the
head of the talus downward between the
calcaneus and the navicular, and this
force is resisted by the spring ligament.7
This downward motion is accompanied
by eversion of the calcaneus at the subtalar joint and slight depression of the
navicular.4 In the normal foot, the lateral portion of the MLA rests on the
ground. This contact, in addition to the
absorption of forces at allfivemetatarsal
heads, offers additional support to the
foot (Fig. 2).
In the properly aligned foot, the calcaneus is in a vertical position, perpendicular to the horizontal metatarsal
heads. Because the metatarsals must remainflaton thefloorfor weight bearing,
their positional relationship with the calcaneus and thus the shape of the MLA
are controlled by the plantar aponeurosis. Hicks found that the plantar aponeurosis absorbed about 60% of the
stress of weight bearing.12,13 As the toes
are extended during the push-off phase
of gait, the increased tension in the plantar aponeurosis raises the MLA by facilitating supination (Fig. 3). This mecha-
Fig. 2. Normal foot. Weight bearing is distributed evenly on all five metatarsal heads.
tendons are attached to the foot behind
the medial malleolus and under the
MLA, also offer support and act like a
sling.7 Evidence exists, however, that the
muscles related to the arch are inactive
during standing and that the ligaments
Fig. 3. Windlass effect. Tightening of the
plantar aponeurosis on push-off increases
the medial longitudinal arch. This increase
stabilizes the foot during ambulation as
weight is shifted onto the ball of the foot.
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689
nism is known as the windlass effect.13
The pronation that occurs immediately
on weight bearing slightly flattens the
MLA, which aids in the absorption of
shock.
PES CAVUS
In the extremely high-arched foot
characteristic of pes cavus, weight bearing is distributed unevenly along the
metatarsal heads and along the lateral
border of the foot (Fig. 4). This type of
disorder causes the foot to be prone to
metatarsal head and calcaneal contusions resulting from the excessive pressure of weight bearing. The foot also is
prone to osteophyte formation at the
junction of the metatarsal bases and the
cuneiforms. This area is quite prominent under the skin and quite susceptible to damage.8
To identify pes cavus, the patient
should sit at the edge of a tabletop with
his foot dangling in a nonweight-bearing
position. If the forefoot is lower than the
heel and the arch is high but depresses
on weight bearing, the patient's condition may be diagnosed as "flexible" pes
cavus. If the arch remains high when the
patient is in a full weight-bearing position, the condition is "rigid" pes cavus.14
The foot with flexible pes cavus usually displays a callus under the second
metatarsal head. This condition is
caused by the arch's inability to dissipate
forces and lack of shock absorption. The
foot with flexible pes cavus responds
well to orthotic devices, which support
the MLA, balance the foot, and provide
shock absorption.
The foot with rigid pes cavus poses
additional problems. Besides callus formation under the first, second, and fifth
metatarsal heads, these feet have tight,
cordlike plantar fascia resulting from the
stresses created by the high arch. The
abnormal stresses produced by the structural problems of a rigid, high-arched
foot also tighten the Achilles tendon and
produce claw toes.9
Because of poor shock absorption and
a very small weight-bearing area, feet
with eitherflexibleor rigid pes cavus are
prone to heel pain and stress fractures,
in addition to various shock-related
pathological conditions that are transmitted up the leg to the knees and
hips 8,10,14,15 Both types of pes cavus usu_
ally are accompanied by excessive inversion at the subtalar joint and supination of the forefoot at the transverse
tarsal joint (Fig. 5).4 Calluses develop
under the metatarsal heads when abnormal weight bearing must be accommo-
dated. The forces of weight bearing commonly are shifted to the dropped head
of the second metatarsal, causing plantar callus formation.16
Treatment for this condition should
be directed at providing arch support,
structural alignment, and shock absorption through the use of orthotic devices
and should include stretching of tight
musculature throughout the lower limb.
The orthotic device for a high-arched
foot usually is made of soft, flexible
materials to increase foot shock absorption. These softer, flexible materials
often compromise joint control, however, making treatment for this condition more difficult. The physical therapist can further help the patient with pes
cavus by evaluating the lower limb for
muscular imbalances. Tight ankle inverter and plantar flexor muscles and
weak ankle everter muscles often accompany pes cavus. Stretching the
tibialis posterior and the gastrocnemiussoleus complex and strengthening the
peroneal muscles will help to balance
the foot's supporting structures in an
effort to restore the foot to its proper
alignment.
PES PLANUS
In pes planus, the head of the talus is
displaced medially and plantarward
from the navicular. This displacement
stretches the spring ligament and the
tendon of the tibialis posterior muscle,
Fig. 4. Foot with pes cavus. Weight bearing
is on the lateral border of the foot and first,
second, and fifth metatarsal heads.
Fig. 5. Supinated foot with pes cavus. Note
the inversion at the subtalar joint.
resulting in the loss of the MLA.16 Because of this medial displacement of the
talar head, a callus may develop where
the prominent talar head presses against
the medial counter of the shoe. When
viewed from the posterior aspect of the
foot, the calcaneus will be everted. The
person whose calcaneus is in valgus will
have a relativelyflat-archedfoot because
of the untwisting of the interconnecting
ligaments of the forefoot and the hindfoot. If the MLA is absent in both seated
and standing positions, the patient has
"rigid" flatfoot. If the MLA is present
while the patient is sitting or is standing
up on the toes, but disappears during
foot-flat stance, he has "supple" flatfoot,
which is correctable with arch supports.16
The flattening of the MLA disrupts
the normal process of weight bearing
and causes functional changes in the
foot. Many people with pes planus demonstrate a flat-footed gait with no toeoff,10 often associated with a large plantar weight-bearing surface (Fig. 6).
Symptoms include a pronated foot, a
shortening of the everter muscles of the
foot (ie, the peroneal muscles), tenderness of the plantar fascia, and laxity of
the supporting structures of the medial
side of the foot (ie, the medial ligaments
or deltoid group) and the tibialis posterior tendon.17 Over time, this functional
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PHYSICAL THERAPY
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Fig. 6. Foot with pes planus. Note large
weight-bearing surface with main force absorption on first and second metatarsal
heads.
ray. Pronation is a component of a more
complex motion, eversion. Eversion of
the forefoot is a combination of movements in all three planes (ie, pronation,
dorsiflexion, and abduction).1,4,5
In the initial phase of gait, the foot
contacts the ground in supination. This
inversion of the calcaneus at the subtalar
joint locks the forefoot and provides the
rigid lever to absorb the force of heelstrike. Immediately after heel-strike, the
hindfoot pronates to unlock the transverse tarsal joint and create a loosepacked position in the forefoot. As the
posterior aspect of the calcaneus rolls
laterally, the sustentaculum tali of the
talus rolls medially, producing the pronation.1119 The direct effect of this pronation is to create a shortening of the
lower limb immediately after heelstrike, while providing a small degree of
shock absorption.3 This change allows
the foot greater flexibility of movement
to adapt to changing ground surfaces.
When the foot overpronates during this
phase, the tibia also rotates medially,
causing the knee to flex earlier than
deformity will develop into a chronic
structural deformity, and abnormal
stresses will be transferred to more proximal areas, affecting the knees, hips, and
low back.
Pes planus is not necessarily symptomatic. Many cases of fallen arches are
painless because the foot adapts by
changing the shape of bones and by the
stretching of ligaments. The structural
changes that accompany a flat-arched
foot, however, affect the normal biomechanics of the lower extremity. Pronation, which is a normal component
of gait, becomes exaggerated in the foot
with pes planus. The lack of an arch
maintains the foot in a flexible, unstable
position, hindering normal gait and creating a wide variety of compensatory
pronation disorders. An understanding
of the components of pronation and its
role during gait is necessary before the
compensatory pronated foot can be discussed.
COMPENSATORY PRONATION
PRONATION AND GAIT
Pronation is an integral component
of the stance phase of gait. Normal pronation is 4 to 8 degrees.15,18 Pronation
for a foot with pes planus is between 10
and 12 degrees.15 Pronation of the forefoot, which causes flattening of the
MLA, also flattens the transverse arch
by splaying or spreading the metatarsals.
The movements of pronation and supination are produced when the foot rotates around its long axis, the second
PRACTICE
normal. This flexion puts abnormal
stresses on the quadriceps femoris muscles, which are contracting eccentrically
to control knee flexion.4
In the late stance phase of gait, the
foot again must function more as a rigid
lever. This action requires an elevated
arch and a locked forefoot. The foot
inverter muscles, in addition to the secondary actions of the triceps surae and
tibialis anterior muscles, cause the calcaneus to invert at the subtalar joint.
This inversion produces supination at
the transverse tarsal joint and lateral
rotation of the tibia.11 The act of supination causes the osteoligamentous
plate of the MLA to twist and tighten,
which elevates the arch and locks the
foot, providing the rigid lever needed for
push-off.
A flat-footed person requires more
muscle action than a nonflat-footed person to support and propel the weight of
his body.2 In pes planus, the hindfoot is
in valgus (Fig. 7). This eversion at the
subtalar joint creates an untwisted foot
with little or no ligamentous support. If,
at heel-strike, this foot makes impact in
the valgus position, the foot is mobile
already and is unprepared to act as a
rigid lever to absorb these ground forces.
The foot, therefore, must rely on accessory muscles for stabilization. This activity fatigues not only the extrinsic
muscles but also the intrinsic muscles of
the foot, which are functioning maximally to compensate for the lack of
ligamentous support.
Fig, 7. Pronated foot with pes planus. Note
the eversion at the subtalar joint and the
medial displacement of the talus and navicular.
The most common pathomechanical
problem associated with pes planus is
compensatory pronation. Overpronation and pes planus are key factors in
preventing the subtalar joint from locking during the complex biomechanical
functioning of the lower extremity. This
failure of the subtalar joint to lock creates a hypermobile foot, setting the stage
for structural deformities and problems
throughout the lower quarter. The physical therapist can use three static observations to detect abnormal pronation:
1) Helbing's sign, the medial bowing of
the Achilles tendon secondary to calcaneal valgus; 2) Feiss's line, indicating
the position of the navicular in relation
to a line drawn between the first metatarsophalangeal joint and the medial
malleolus; and 3) the amount and placement of callus formation, usually
thicker under thefirstand second metatarsal heads and the medial, plantar surface of the calcaneus.15
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691
A common cause of overpronation is
a limitation of muscular flexibility anywhere along the lower limb. A tight
triceps surae causes an early heel-off,
which does not allow adequate time for
resupination.15 Tight hamstring, hip
flexor, iliotibial band, and hip medial
rotator muscles all produce a toe-out
gait. Toeing out prevents the foot from
resupinating before toe-off, leaving a
flexible, unstable foot.
Compensatory pronation is associated often with other lower extremity
disorders. In the patient with a leglength discrepancy, excessive pronation
of the foot generally is a telltale sign of
a longer limb.15 This pronation is accompanied usually by early knee flexion
and longer stance time on the longer
limb. In runners who train on paved
roads, a functionally longer limb is created unconsciously by the "crowning"
of the road. The sloped surface of the
road will cause pain on the "downside"
leg, the functionally longer limb. On a
small track with sharp-banked curves,
medial knee pain usually will occur on
the "inside" leg. Forces are transmitted
up the leg as the downside foot overpronates in an attempt to make a functionally longer limb shorter.
Another common cause of overpronation is forefoot varus (Fig. 8). This
disorder can be detected by sitting the
patient on a treatment table with his
foot hanging over the edge of the tabletop. With the subtalar joint in a neutral
position, the forefoot will hang in an
inverted position at rest. This congenital
deformity originates as a supinated foot,
but gravity pulls the medial aspect of
the foot down when making contact
with the ground during weight bearing.
The foot thus becomes excessively pronated because of the overcompensation
of bringing the foot to the ground. In
addition to the common problems of
tight peroneal muscles and stresses up
the lower extremity, which can lead to
such problems as shin splints, Hughes
found that soldiers with a greater than
normal forefoot varus are 8.3 times
more likely to develop a stress fracture
than soldiers with normal forefoot varus.20 A valgus deformity causes the first
metatarsal to contact the ground before
the fifth metatarsal, which forces all
loads to the medial aspect of the foot.
The first metatarsal head is twice the
size and can absorb 2.6 times the force
of the second metatarsal head.20 The
head and shaft of the second metatarsal
of the overpronating foot with pes
planus, therefore, commonly develop
Fig. 8. A. Normal relationship between the hindfoot and forefoot. Note that the calcaneus
and metatarsal heads are perpendicular. B. Forefoot varus. The forefoot rests in an inverted
position relative to the subtalar joint, which is in a neutral position. (Adapted from Wallace.15)
callosities and stress fractures, respectively.
Overpronation of the forefoot can
lead to subsequent malalignments of the
entire lower limb. In response to overpronation, the tibia will rotate medially.
In these patients, the hip adductor muscles will be tight, and the external rotator
muscles will be weak. The knee tends to
assume a valgus position when the foot
pronates. The distractive forces on the
medial side of the knee lead to medial
knee pain. The increased valgus also
affects the proper tracking mechanism
of the patella, predisposing the knee to
chondromalacia and other patella tracking dysfunctions.1017 Unilateral pronation, if allowed to progress to more cephalic joints, will lead to a scoliosis.
Bilateral pronation will increase the lordosis of the lumbar spine.21 Decreasing
pronation appears to increase the stability of the extensor mechanism of the
knee and decrease runners' knee symptoms.22
Treatment for the overpronated foot
with pes planus should revolve around
reducing the stresses that caused the
problem. Long-distance runners with
foot, knee, or hip pain secondary to pes
planus should reduce their mileage, or
perhaps even temporarily stop running,
to allow the tissues to heal. A muscle
strengthening program to strengthen the
anterior and posterior tibialis and intrinsic foot muscles might increase the muscular support of the arch, forcing muscles to absorb most of the load. Other
treatments include arch taping or supports, ultrasound to heal damaged tissues, stretching of tight muscle groups,
and orthotic devices. An understanding
of the principles behind the use of orthotic devices will enable the physical
therapist to correct both pes cavus- and
pes planus-related problems by realigning the weight-bearing surfaces of the
foot.
ORTHOTIC DEVICES
After a comprehensive lower extremity evaluation applying their background knowledge of the anatomy and
kinesiology of normal foot function,
physical therapists should be able to
construct foot orthoses to balance the
body's base of support. By following
several simple principles and using readily available, inexpensive materials, normal foot function can be restored in
minutes.
An orthosis is a soft, semiflexible or
rigid, device whose purpose is to balance
the foot in the neutral position during
the gait cycle. Soft, temporary supports
can be made by adding felt and other
soft materials to the insoles of the shoes.
These materials, which will adapt to the
contours of the foot, help correct problems such as abnormal pronation and
supination, offer metatarsal and arch
support, and provide better shock absorption. The main function of an orthotic device is to provide a combination of neuromuscular reeducation and
a change in body mechanics in an atPHYSICAL THERAPY
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PRACTICE
Fig. 9.
Structural tripod of the foot: the calcaneus and the first and fifth metatarsal heads.
tempt to readjust the foot into a more
ideal weight-bearing position. Arch supports support the arch of the foot; however, they do not balance or offer mechanical control to the foot.
When making orthotic devices for a
patient, several principles should be kept
in mind. Most important, undercorrection is the preferred treatment protocol.
Maximal foot control is unnecessary,
and a balancing effect of the foot is best.
Visualize the foot as a structural tripod,
with the heel and the first and fifth
metatarsals as the bases of support (Fig.
9). The purpose of the orthotic device is
to fill in the space between the balanced
foot and the ground. Imagine bringing
the ground up to the foot. When correcting an overpronating foot, remember that the foot has a natural tendency
to pronate to some degree, usually 4 to
8 degrees.15,18 An orthotic device should
not block all pronation. In addition, an
entire lower quarter examination must
be performed involving an assessment
of muscle strength and flexibility and
proper joint function.
An orthotic device consists of two
basic parts: 1) the base, the material you
start with, and 2) the post, or the extra
material that is added to the base to
"bring the ground up to the foot." In
forefoot varus, the medial aspect of the
foot is posted. Most compensatory pronation problems can be corrected by
balancing in this manner.23 In the patient with anteromedial knee pain
caused by excessive pronation, orthotic
devices balance the heel at contact, support the arch at mid-stance, and allow
eversion at the subtalar joint just before
push-off.24 For pes cavus, a 0.25-in* felt
heel lift and a lateral 0.12-in forefoot
extension between the lateral half of the
hindfoot and the fourth and fifth metatarsal heads have been found to be helpful.22
Soft, temporary supports wear down
quickly, and readjustments must be
made as needed. A wide variety of temporary orthotic devices can be made on
the spot with minimal supplies and
time.15,25,26 When making temporary orthotic devices for a patient, the physical
therapist might want to use athletic tape
either to tape the posting materials into
the shoes or to bind the patient's feet
into the desired position. When the correct temporary support is given and foot
function has improved substantially, a
*1in = 2.54 cm.
permanent orthotic device should be
custom made.
Permanent orthotic devices are made
from a positive model cast of the foot.
The two methods most often used are
the foam box impression and a plasterof-Paris slipper cast impression, both
taken with the subtalar joint held in a
neutral position. The neutral position of
the foot is maintained when the long
axis of the lower limb and the vertical
axis of the calcaneus are parallel. Thermoplastic, or heat pliable, orthotic materials are molded onto the positive
models to form the base. Postings and
more durable materials then are added
to complete the correction.
In unidirectional sports, such as running, an orthosis can help the foot attain
a neutral position at the middle of midstance. Rigid orthotic devices, made
from a hard plastic material, are preferred by runners and by patients for use
during walking and normal daily activities. In sports in which pivoting is involved or multidirectional forces are
placed on the foot, the orthosis must
provide arch control while allowing
eversion at the subtalar joint to offer
more forefoot flexibility.22 Semiflexible
orthotics, made of leather and more pliable materials, are preferred by these
athletes.
SUMMARY
The arches of the foot play an integral
role in determining the proper mechanics of the entire lower limb. Both pes
cavus and pes planus demonstrate typical patterns of structural deformity.
Through an understanding of lower
limb biomechanics, the physical therapist can evaluate and recognize structural imbalances and other disorders
that originate with the arch of the foot.
When detected, various related, symptomatic pathological conditions may be
treated and relieved by balancing the
foot through the use of orthotic devices.
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PHYSICAL THERAPY
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Pes Cavus and Pes Planus: Analyses and Treatment
Abby Herzog Franco
PHYS THER. 1987; 67:688-694.
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