lower limb foot

Anatomy of The Foot

By:Dr Mohammed Faez

Anatomy of The Foot

• The foot is the region of the lower limb distal to the ankle joint.

• It is subdivided into the tarsus, the metatarsus, and the digits.

• The foot has a superior surface (dorsum of foot) and an inferior surface (sole)

Anatomy of The Foot

Bones There are three groups of

bones in the foot :• The seven tarsal bones.• Metatarsals (1 to 5).• The phalanges, which

are the bones of the toes-each toe has three phalanges, except for the great toe, which has two.

Anatomy of The Foot

Tarsal bones:The tarsal bones are arranged in a proximal group and a distal group with an intermediate bone between the two groups on the medial side .

Anatomy of The Foot

• The proximal group consists of two large bones, the talus and the calcaneus.

• The intermediate tarsal bone on the medial side of the foot is the navicular.

• The distal group of tarsal bones consists of cuboid and three cuneiforms bons.

Anatomy of The Foot

Metatarsals:There are 5 metatarsals in the foot, numbered I to V from medial to lateral. 1st Metatarsal bone associated with the great toe, is shortest and thickest. The 2nd is the longest.

Anatomy of The Foot

Phalanges The phalanges are the bones of the toes. Each toe has three phalanges (proximal, middle, and distal), except for the great toe, which has only two (proximal and distal).

Read about

Foot’s Joints

Tarsal tunnel

The 'tarsal tunnel' is formed on the posteromedial side of the ankle by:

• A depression formed by the medial malleolus of the tibia, the medial and posterior surfaces of the talus, the medial surface of the calcaneus, and the inferior surface of the sustentaculum tali of the calcaneus.

• An overlying flexor retinaculum .

Tarsal tunnel

• The flexor retinaculum is a strap-like layer of connective tissue.

• It attaches above to the medial malleolus and below and behind to the inferomedial margin of the calcaneus.

Contents of Tarsal tunnel

• Tibialis posterior muscle• Flexor digitorum longus

muscle• Posterior tibial artery• Posterior tibial vein• Tibial nerve• Flexor hallucis longus

muscle(mnemonic used is "Tiny

Dogs Are Not Hunters“)

Extensor retinacula

Two extensor retinacula strap the tendons of the extensor muscles to the ankle region and prevent tendon bowing during extension of the foot and toes:

• Superior extensor retinaculum

• Inferior retinaculum

Plantar Aponeurosis• It is a thickening of deep

fascia in the sole of the foot.• It is firmly anchored to the

medial process of the calcaneal tuberosity and extends forward as a thick band of longitudinally arranged connective tissue fibers.

• The plantar aponeurosis supports the longitudinal arch of the foot and protects deeper structures in the sole.

Arches of the foot

• The bones of the foot form longitudinal and transverse arches relative to the ground which absorb and distribute downward forces from the body during standing and moving on different surfaces.

Arches of the foot

Longitudinal archIt is formed between the posterior end of the calcaneus and the heads of the metatarsals. It is highest on the medial side where it forms the medial part of the longitudinal arch and lowest on the lateral side where it forms the lateral part.

Arches of the foot

Arches of the foot

Longitudinal arch• Medial longitudinal arch• Lateral longitudinal arch

Arches of the foot

Transverse archIt runs from medial to lateral direction on the plantar surface of the foot. This arch also provides support and flexibility to the foot.

Arches of the foot

Muscles of the foot

Muscles of the foot are classed as:

• Intrinsic muscles• Extrinsic muscles

Muscles of the foot

Intrinsic muscles originate and insert in the foot and control the movement of the toes.

Extrinsic muscles originate from anywhere in the lower leg, their long tendons cross the ankle joint and insert onto one of the bones of the foot.

Arteries of the foot

Blood supply to the foot is by branches of the posterior tibial and dorsalis pedis (dorsal artery of the foot) arteries

Arteries of the foot

Posterior tibial artery and plantar arch:

• The posterior tibial artery enters the foot through the tarsal tunnel on the medial side of the ankle and posterior to the medial malleolus.

• It bifurcates into a small medial plantar artery and a much larger lateral plantar artery.

Arteries of the foot Dorsalis pedis artery :• It is the continuation of the

anterior tibial artery and begins as the anterior tibial artery crosses the ankle joint .

• It passes anteriorly over the dorsal aspect of the talus, navicular, and intermediate cuneiform bones, and then passes inferiorly, as the deep plantar artery, between the two heads of the first dorsal interosseous muscle to join the deep plantar arch in the sole of the foot.

Arteries of the foot

Dorsalis pedis artery :• Pulse of the dorsalis pedis

artery on the dorsal surface of the foot can be felt by gently palpating the vessel against the underlying tarsal bones between the tendons of extensor hallucis longus and the tendon of extensor digitorum longus to the second toe.

Veins of the foot

Veins of the foot :• Deep veins• Superficial veins

The deep veins follow the arteries.

Veins of the foot Superficial veins drain into a dorsal

venous arch on the dorsal surface of the foot over the metatarsals:

• The great saphenous vein originates from the medial side of the arch and passes anterior to the medial malleolus and onto the medial side of the leg

• The small saphenous vein originates from the lateral side of the arch and passes posterior to the lateral malleolus and onto the back of the leg.

Nerves of the foot

The foot is supplied by the tibial, deep peroneal, superficial peroneal, sural, and saphenous nerves.