Chapter 19
The Leg, Foot and Ankle
Overview
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The ankle and foot is a complex structure
comprised of 28 bones (including 2
sesamoid bones) and 55 articulations
(including 30 synovial joints),
interconnected by ligaments and muscles
In addition to sustaining substantial forces,
the foot and ankle serve to convert the
rotational movements that occur with
weight bearing activities into sagittal,
frontal, and transverse movements
Anatomy
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Anatomically and biomechanically, the foot
is often subdivided into:
The rearfoot or hindfoot (the talus and
calcaneus)
The midfoot (the navicular, cuboid and the 3
cuneiforms)
The forefoot (the 14 bones of the toes, the
5 metatarsals, and the medial and lateral
sesamoids)
Anatomy
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Distal Tibiofibular Joint
– Classified as a syndesmosis
– Consists of a concave tibial surface and a
convex or plane surface on the medial
distal end of the fibula
Anatomy
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The talocrural (ankle) joint
Formed between the saddle-shaped
talus and the distal tibia
Classified as a synovial hinge or a
modified sellar joint
Anatomy
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Subtalar (talocalcaneal) joint
– The subtalar joint is a synovial, bicondylar
compound joint consisting of two separate,
modified ovoid surfaces with their own joint
cavities (one male and one female)
– This relationship ensures that the anterior and
posterior aspects can move in opposite
directions to each other during functional
movements (while the anterior aspect is moving
medially, the posterior aspect is moving laterally)
Anatomy
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Talocalcaneal joint ligaments
– A number of ligaments provide support to
this joint, although some confusion exist
in the descriptions and nomenclature of
these ligaments
The two superficial ligaments are the lateral
and posterior talocalcaneal ligaments
 The deep ligaments include the interosseous,
cervical, and axial ligaments, often referred
together as the interosseous ligaments
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Anatomy
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The midtarsal joint complex
– Consists of the talonavicular and
calcaneocuboid articulations
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The talonavicular joint is classified as a
synovial, compound, modified ovoid joint
– Formed by components of the talus, navicular,
calcaneus and plantar calcaneonavicular (spring)
ligament
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The calcaneocuboid joint is classified as a
simple, synovial modified sellar joint
Anatomy
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Ligaments of the mid-tarsal joints
– A number of ligaments help provide
support to this region:
The spring ligament (plantar
calcaneonavicular) connects the navicular
bone to the sustentaculum tali on the
calcaneus
 The ligaments of the calcaneocuboid joint
include the long plantar ligament and a
portion of the bifurcate ligament dorsally
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Anatomy
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The cuneonavicular joint
– Classified as a compound, synovial,
modified ovoid joint
Anatomy
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Intercuneiform and Cuneocuboid
Joints
– These joints are classified as compound,
synovial, modified ovoid joints
Anatomy
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Cubometatarsal joint
– When considered alone, this joint is
classified as a compound modified ovoid,
synovial joint
Anatomy
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The cubonavicular joint
– Classified as a syndesmosis, or a plane
surfaced joint
Anatomy
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Intermetatarsal joints
– The first intermetatarsal joint is classified
as a simple, synovial, modified ovoid
joint, while the 2nd, 3rd and 4th are
classified as compound joints
Anatomy
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The metatarsophalangeal (MTP) joints
– Classified as simple, synovial, modified
ovoid joints
Anatomy
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The interphalangeal (IP) joints
– Classified as simple, synovial modified
sellar joints
Anatomy
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Plantar fascia/aponeurosis
– The plantar fascia is the investing fascial layer of
the plantar aspect of the foot that originates
from the os calcis and inserts through a complex
network to the plantar forefoot
– A tough, fibrous layer, composed histologically of
both collagen and elastic fibers
– Three portions
Anatomy
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Plantar fascia/aponeurosis
– With standing and weightbearing, the
plantar fascia plays a major role in the
support of the weight of the body by
virtue of its attachments across the
longitudinal arch.
Anatomy
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Retinacula
– There are four important ankle retinacula,
which function to tether the leg tendons
as they cross the ankle to enter the foot
Anatomy
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The extrinsic muscles of the foot
– Can be divided into anterior, posterior
superficial, posterior deep, and lateral
compartments
Anatomy
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The extrinsic muscles of the foot
– Anterior compartment
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This compartment contains the dorsiflexors (extensors)
of the foot. These include the tibialis anterior, extensor
digitorum longus, extensor hallucis longus, and
peroneus tertius
– Posterior superficial compartment
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This compartment, located posterior to the
interosseous membrane, contains the calf muscles
which plantarflex (flex) the foot. These include the
gastrocnemius, soleus, and the plantaris muscle
Anatomy
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The extrinsic muscles of the foot
– Posterior deep compartment
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This compartment contains the flexors of the
foot. These muscles include the posterior
tibialis, flexor digitorum longus, and flexor
hallucis longus
– Lateral compartment
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This compartment contains the peroneus
longus and brevis
Anatomy
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The intrinsic muscles of the foot
– Subdivided into 4 layers
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1st layer:
– Abductor hallucis
– Abductor digiti minimis
– Flexor digitorum brevis
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2nd layer
– Flexor digitorum accessorius (quadratus plantae)
– Lumbricales
Anatomy
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The intrinsic muscles of the foot
– 3rd layer
Flexor hallucis brevis
 Flexor digiti minimis
 Adductor hallucis
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– 4th layer
Dorsal interossei
 Plantar interossei
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Anatomy
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The dorsal intrinsic muscles of the foot
– Consist of the extensor hallucis brevis
(EHB) and extensor digitorum brevis
(EDB) muscles
Anatomy
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Arches of the foot
– There are 3 main arches:
The medial longitudinal
 The lateral longitudinal
 The transverse
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Anatomy
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Neurology
– The saphenous nerve, the largest cutaneous
branch of the femoral nerve, provides cutaneous
distribution to the medial aspect of the foot
– The sciatic nerve provides the sensory and
motor innervation for the foot and leg
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It divides into the common peroneal and tibial nerves.
The common peroneal nerve in turn divides into the
superficial peroneal, deep peroneal nerves. The tibial
nerve divides into the sural, medial calcaneal, medial
plantar, and lateral plantar nerves
Anatomy
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Vascular supply
– Two branches of the popliteal artery, the
anterior tibial artery and the posterior
tibial artery, form the main blood supply
to the foot
Biomechanics
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Terminology
– Motions of the leg foot and ankle consist of
single plane and multi-plane movements. The
single plane motions include:
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The frontal plane motions of inversion and eversion
The sagittal plane motions of dorsiflexion and
plantarflexion
The horizontal plane motions of adduction and
abduction
Biomechanics
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A triplane motion describes a
movement about an obliquely oriented
axis through all three body planes.
Triplanar motions occur at the
talocrural, subtalar, and midtarsal,
joints, and at the first and fifth rays.
Pronation and supination are
considered triplanar motions
Biomechanics
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Pronation
– The three body plane motions in
pronation are abduction in the transverse
plane, dorsiflexion in the sagittal plane,
and eversion in the frontal plane
Biomechanics
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Supination
– The three body plane motions in
supination are a combined movement of
adduction, plantarflexion, and inversion
Biomechanics
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Proximal tibiofibular joint
– Because of the interaction between the
proximal and distal tibiofibular joints with
the knee and the ankle function, the
clinician should always evaluate the
functional mobility of both these
complexes when treating one or the other
Biomechanics
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Talocrural Joint
– The primary motions at this joint are dorsiflexion
and plantar flexion, with a total range of 70-80°
– Theoretically, the capsular pattern of the ankle
joint is more restriction of plantarflexion than
dorsiflexion, although clinically this appears to
be reversed
– The close-packed position is weight-bearing
dorsiflexion, while the open-packed position is
midway between supination and pronation.
Biomechanics
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The subtalar joint
– Subtalar joint supination and pronation
are measured clinically by the amount of
calcaneal or hindfoot inversion and
eversion
– In normal individuals, there is an
inversion to eversion ratio of 2:3 to 1:3,
which amounts to approximately 20° of
inversion and 10° of eversion
Biomechanics
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Subtalar joint
– The capsular pattern of this joint varies.
In chronic arthritic conditions, there is an
increasing limitation of inversion, but with
traumatic arthritis, eversion appears most
limited clinically
– The close-packed position for this joint is
full inversion, while the open-packed
position is inversion/plantarflexion
Biomechanics
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The midtarsal joint complex
– Provides the foot with an additional mechanism for raising
and lowering the arch, and to absorb some of the
horizontal plane tibial motion that is transmitted to the
foot during stance
– The talonavicular joint two degrees of freedom: plantar
flexion/dorsiflexion and inversion/eversion, with motion
occurring around a longitudinal and oblique axis, both of
which are independent of each other
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The capsular pattern is a limitation of dorsiflexion, plantar
flexion, adduction and internal rotation
The close packed position is pronation
The open packed position is midway between extremes of
range of motion
Biomechanics
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The midtarsal joint complex
– The capsular pattern for the
calcaneocuboid joint is a limitation of
dorsiflexion, plantar flexion, adduction
and internal rotation
Biomechanics
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The cuneonavicular joint
– Has one to two degrees of freedom:
plantar/dorsiflexion, inversion/eversion
– The capsular pattern is a limitation of
dorsiflexion, plantar flexion, adduction and
internal rotation
– The close-packed position is supination
– The open-packed position is considered to be
midway between the extremes of range of
motion
Biomechanics
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Intercuneiform and Cuneocuboid Joints
– Due to their very plane curvature, these joints
have only one degree of freedom:
inversion/eversion
– The close packed position for these joints is
supination
– The open packed position is considered to be
midway between extremes of range of motion
Biomechanics
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Cubometatarsal Joint
– The capsular pattern of this joint is a
limitation of dorsiflexion, plantar flexion,
adduction and internal rotation
– The close-packed position is pronation.
– The open-packed position is considered
to be midway between extremes of range
of motion
Biomechanics
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Cubonavicular Joint
– The close-packed position for this joint is
supination
– The open-packed position is midway
between extremes of range of motion
Biomechanics
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Intermetatarsal Joints
– The close-packed position for these joints
is supination
– The open-packed position is midway
between extremes of range of motion
Biomechanics
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Metatarsophalangeal Joints
– The MTP joints have two degrees of freedom:
flexion/extension and abduction/adduction.
– Range of motion of these joint is variable,
ranging from 40° to 100° dorsiflexion (with a
mean of 84°), 3° to 43° (mean, 23°) plantar
flexion, and 5° to 20° varus and valgus
– The closed-packed position for the MTP joints is
full extension
– The capsular pattern for these joints is variable,
with more limitation of extension than flexion
– The open-packed position is 10º of extension.
Biomechanics
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1st Metatarsophalangeal Joint
– The function of the great toe is to provide
stability to the medial aspect of the foot, and to
provide for normal propulsion during gait.
Normal alignment of the 1st MTP joint varies
between 5° varus and 15° valgus
– The great toe is characterized by having a
remarkable discrepancy between active and
passive motion. Approximately 30° of active
plantar flexion is present, and at least 50° of
active extension, which can be frequently
increased passively to between 70-90°.
Biomechanics
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Interphalangeal (IP) Joints
– Each of the IP joints has one degree of
freedom: flexion/extension
– The capsular pattern is more limitation of
flexion than of extension
– The close-packed position is full extension
– The open-packed position is slight flexion
Examination
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The examination is used to identify static
and dynamic, structural or mechanical foot
abnormalities
The clinical diagnosis is based on an
assessment of the changes in joint mobility
and tissue changes at the foot and ankle,
and the effect these have on the function of
the remainder of the lower kinetic chain
Examination
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History
– The primary purposes of the history are to:
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Determine the severity of the condition
Determine the area, nature and behavior of the
symptoms
Help determine the specific structure at fault
Detect systemic conditions (collagen disease,
neuropathy, radiculopathy, and vascular problems), or
the presence of serious pathology
Examination
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Systems Review
– As symptoms can be referred distally to the leg, foot and
ankle from a host of other joints and conditions, the
clinician must be able to differentially diagnose from the
presenting signs and symptoms
– The cause of the referred symptoms may be neurological
or systemic in origin. If a disorder involving a specific
nerve root (L 4, L 5, S1, or S 2) is suspected, the
necessary sensory, motor and reflex testing should be
performed
– Peripheral nerve entrapments, although not common, may
also occur in this region and often go unrecognized
Examination
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Systems Review
– Systemic problems that may involve the
leg, foot and ankle include diabetes
mellitus (peripheral neuropathy),
osteomyelitis, gout and pseudogout,
sickle cell disease, complex regional pain
syndrome, peripheral vascular disease,
and rheumatoid arthritis
Examination
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Observation
– Observation of the lower extremity is extensive.
It is extremely important to observe the entire
kinetic chain when assessing the leg, foot, and
ankle. Weight bearing and non-weight bearing
postures of the foot are compared.
– Observing the patient while they move from sit
to stand, and walk to the treatment area, gives
the clinician a sense of the patient’s functional
ability in weight bearing, and provides the first
opportunity for gait analysis.
Examination
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Palpation
– Careful palpation should be performed
around the leg, foot, and ankle to
differentiate tenderness of specific
ligaments and other structures
– Areas of localized swelling and
ecchymosis over the ligaments on the
medial or lateral aspects of the foot and
ankle should be noted
Examination
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Active and Passive Range of Motion
– AROM tests are used to assess the patient’s
willingness to move and the presence of
movement restriction patterns such as a
capsular on non-capsular pattern
– General active range of motion of the foot and
ankle in the non-weight bearing position is
assessed first, with painful movements being
performed last
– In addition to the foot and ankle tests, the
clinician should also assess hip and knee range
of motion
Examination
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Strength testing
– Isometric tests are carried out in the extreme
range, and if positive, in the neutral range
– The straight plane motions of ankle dorsiflexion,
plantar flexion, inversion and eversion are tested
initially. Pain with any of these tests requires a
more thorough examination of the individual
muscles
Examination
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Strength testing
– The individual isometric muscle tests can give
the clinician information about patterns of
weakness other than from spinal nerve root or
peripheral nerve palsies and can also help to
isolate the pain generators
– A painful weakness is invariably a sign of serious
pathology, and depending on the pattern, could
indicate a fracture or a tumor. However, if a
single motion is painfully weak this could
indicate muscle inhibition due to pain.
Examination
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Strength testing
– Weakness on isometric testing needs to be
analyzed for the type:
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Increasing weakness with repeated contractions of the
same resistance indicating a palsy
Consistent weakness with repeated contractions which
could suggest a deconditioned muscle, or a significant
muscle tear), and the pattern of weakness (spinal
nerve root, nerve trunk or peripheral nerve)
Examination
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Passive articular mobility
– Passive articular mobility tests assess the
accessory motions available between the
joint surfaces. These include tests of the
joint glides, joint compression and joint
distraction tests. As with any other joint
complex, the quality and quantity of joint
motion must be assessed to determine
the level of joint involvement
Examination
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Special tests
– Special tests are merely confirmatory tests
– Selection for their use is at the discretion of the
clinician and is based on a complete patient
history
– The results from these tests are used in
conjunction with the other clinical findings and
should not be used alone to form a diagnosis
– To assure accuracy with these tests, both sides
should be tested for comparison
Examination
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Neurological tests
– Important neurological structures that pass
through the ankle and terminate in the foot are
the saphenous, superficial peroneal, deep
peroneal, posterior and anterior tibial nerves,
and the sural nerve
– Symptoms can be referred to the foot and ankle
from the L 4-S 2 nerve roots (sciatic) and from a
host of non-neurological conditions
Examination
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Neurological tests
– Common reflexes tested in this area are
the Achilles reflex (S 1-2), and the
posterior tibial reflex (L 4-5)
– The pathological reflexes (Babinski, and
Oppenheim), tested when an upper
motor neuron lesion is suspected
Intervention
Intervention
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Acute phase goals:
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Decrease pain, inflammation and swelling
Protect the healing area from re-injury
Re-establish pain-free range of motion
Prevent muscle atrophy
Increase neuromuscular control
Maintain fitness levels
Patient to be independent with home exercise
program
Intervention
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Functional phase goals:
– Restore normal joint kinematics
– Attain full range of pain free motion
– Improve neuromuscular control of the lower
extremity in a full weight bearing posture on
both level and uneven surfaces
– Regain and improve lower extremity strength
and endurance through integration of local and
kinetic chain exercises
Intervention