Chapter 17: The Foot
I.
Foot Anatomy
1. Bones
a. Foot consists of 26 bones: 14 phalangeal, 5 metatarsal and 7 tarsal, also 2 sesamoid bones
beneath the first metatarsal
b. Toes
1. Designed to give wider base for balance and for propelling the body
forward
2. First toe has 2 phalanges the remaining toes have 3
3. Sesamoids under the first metatarsal (in the flexor hallucis tendon) assist
with reducing pressure in weight bearing, increase the mechanical
advantage of the flexor tendons of the great toe, act as sliding pulleys for
tendons
c. Metatarsals
1. Five bones that lie between and articulate with the tarsals and the phalanges
2. Ligamentous arrangement gives elasticity to the foot in weight bearing
3. MTP joints permit hinge action of phalanges
4. First metatarsal functions as the main weight bearing support during
walking and running
d. Tarsal Bones
1. Calcaneous
A. Largest tarsal bone; supports the talus and shapes the heel
B. Main functions: convey the body weight to the ground and serves as
attachment of Achilles Tendon and plantar structures
2. Talus
A. Situated above the calcaneous; consists of the body, neck and head
B. Trochlea articulates with the medial and lateral malleoli to form the ankle
joint
C. Dorsiflexion is limited due to talus being narrower posteriorly than
anteriorly
3. Navicular
A. Anterior to the talus on the medial aspect of the foot
B. Articulates with the three cuneiform bones
4. Cuboid
A. On the lateral aspect of the foot
B. Articulates posteriorly with the calcaneous and anteriorly with the fourth
and fifth metatarsals
5. Cuneiforms
A. Three cuneiforms located between the navicular and the base of the three
metatarsals on the medial aspect of the foot
2. Arches of the Foot: Arches provide support in weight bearing, absorb shock, and provide
space on plantar surface of blood vessels, nerves, and muscles
a. Anterior Metatarsal Arch
1. Shaped by the distal heads of the metatarsals
b. Transverse Arch
1. Extends across the cuboid, and the internal cuneiform
2. Protects the soft tissue and increases foot mobility
c. Medial Longitudinal Arch
1. Originates on medial border of the calcaneous and extends forward to the
distal head of the first metatarsal
2. Main supporting ligament = plantar calcaneonavicular ligament (spring
ligament)
3. Tendon of the posterior tibialis muscle helps to support the plantar
calcaneonavicular ligament
d. Lateral Longitudinal Arch
1.
3.
4.
5.
On outer aspect of the foot, formed by the calcaneous, cuboid and fifth
metatarsal bone
Plantar Fascia (Plantar Aponeurosis)
a. Thick white band of fibrous tissue originates on the medial tubercle of the calcaneous and
ends at the proximal heads of the metatarsals
b. Supports the foot against downward forces
Articulations
a. Interphalangeal Joint
1. Designed for flexion and extension
2. Reinforced by collateral ligaments
b. Metatarsophalangeal Joint
1. Condyloid type joints permitting flexion, extension, adduction and
abduction
c. Tarsometatarsal Joint
1. Formed by junction of the bases of the metatarsal bones with the cuboid and
all three cuneiforms – allows for some gliding
2. Also known as the Lisfranc’s joint
d. Subtalar Joint
1. Articulation between the talus and calcaneous
2. Allows for inversion, eversion, pronation, and supination
3. In weight bearing pronation refers to combined movement of talar
plantarflexion and adduction and calcaneal eversion
4. In weight bearing supination refers to combined movement of talar
dorsiflexion, abduction and calcaneal inversion
Muscles and Movement
a. Dorsiflexion: tibialis anterior, extensor digitorum longus, extensor hallucis longus
b. Plantarflexion: Gastrocnemius, soleus,
c. Inversion: Tibialis posterior, flexor digitorum longus, flexor hallucis longus,
d. Eversion: Peroneus longus, peroneus brevis, peroneus tertius
e. Movements of Phalanges
1.
2.
6.
7.
II.
III.
IV.
Nerve Supply and Blood Supply
a. Tibial nerve supplies the muscles on the back of the leg and the plantar aspect of the foot
b. Common peroneal nerve supplies the front of the leg and the foot
Blood Supply
a. Major portion of blood is supplied by the anterior and posterior tibial arteries
Functional Anatomy of Foot Biomechanics
1. Structural Deformities
a. Pes Planus
b. Pes Cavus
Prevention of Foot Injuries
1. Selecting Appropriate Footwear
a. Pronators need stability and firmness to reduce excess motion (need board lasted,
straight lasted shoe, with good rearfoot control)
b. Supinators need cushioning and flexibility as foot is too rigid (need slip lasted or
combination lasted, curve lasted shoe)
Foot Assessment
1. Obtain a thorough history
2. Observation
3. Look for structural Deformities (bunions, check for forefoot varus/valgus deformities, check
for rearfoot varus/valgus deformities, flexibility of first ray)
4. Look at shoe wear patterns
a.
V.
pronators wear out the front of the shoe under the second metatarsal, supinators wear
out the outside of the shoe. All have excessive wear on the lateral heel due to heel
strike
5. Palpation of bony and soft tissue structures
6. Pulses (posterior tibial and dorsalis pedis arteries)
7. Special Tests
a. Tinel’s sign: tap over the posterior tibial nerve – numbness, tingling and paresthesia
may indicate tarsal tunnel syndrome
b. Morton’s Test: Transverse pressure on metatarsal heads causing sharp pain in
forefoot, may indicate presence of neuroma or metatarsalgia
8. Neurological Assessment
a. Check reflexes (achilles = S1) and cutaneous distribution
Recognition and Management of Specific Injuries
1. Injuries to the Tarsal Region
a. Fractures of the Talus
b. Fractures of the Calcaneous
c. Calcaneal Stress Fracture
d. Sever’s Disease (Apophysitis of the Calcaneous)
e. Retrocalcaneal Bursitis
f. Heel Contusion
g. Cuboid Subluxation
h. Lisfranc Injury (Tarsometatarsal Fracture/Dislocation)
2. Injuries to the Metatarsal Region
a. Pes Planus Foot
b. Pes Cavus Foot
c. Longitudinal Arch Strain
d. Plantar Fasciitis
e. Jones Fracture
f. Metatarsal Stress Fracture
g. Hallux Valgus Deformity (Bunion) and Tailor’s Bunions (Bunionettes)
h. Sesamoiditis
i. Metatarsalgia
j. Metatarsal Arch Strain
k. Morton’s Neuroma
3. Injuries to the Toes
a. Sprained Toes
b. Turf Toe
c. Fractures and Dislocations of Phalanges
d. Morton’s Toe
e. Hallux Rigidus
f. Subungual Hematoma (blood under toenail)