Anatomical Basis of Foot Movement

Anatomical Basis of Foot Movement

• The foot comprises seven tarsal bones, five metatarsals, and 14 phalanges
• The tarsus bones include the talus, calcaneus, cuboid, and three cuneiforms (medial, intermediate, and lateral)
• The talus articulates superiorly with the tibia, laterally with the lateral malleolus, and medially with the medial malleolus
• The talus has a body, neck, and head, with a trochlea superiorly.
• The calcaneus is a large, posterior bone, possessing a sustentaculum tali and medial and lateral tubercles
• The cuboid articulates with the fourth and fifth metatarsals.
• The navicular is located between the talus and the cuneiforms.

Ankle Joint

• The ankle joint is a synovial hinge joint, permitting dorsiflexion and plantar flexion
• The joint is reinforced by medial and lateral ligaments.
• The medial (deltoid) ligament is highly strengthened, triangular in shape, and attached to the medial malleolus and the medial tubercle of the talus, spring ligament, and the navicular tuberosity.
• The lateral ligament consists of three separate bands (anterior talofibular, calcaneofibular, and posterior talofibular) originating from the lateral malleolus
• The lateral ligament is weaker than the medial one

Movements of the Ankle Joint

• Dorsiflexion (foot points up): Tibialis anterior, Extensor digitorum longus, Extensor hallucis longus, Peroneus tertius
• Plantar flexion (foot points down): Gastrocnemius, Soleus, Plantaris, Tibialis posterior, Flexor digitorum longus, Flexor hallucis longus

Muscles of the Foot

• The muscles in the foot are organized into the dorsum and sole of the foot
• Dorsum of the foot:Extensor digitorum brevis, extensor hallucis brevis
• Sole of the foot: Muscles and tendons arranged into four layers from below upwards
  • 1st layer: Abductor hallucis, Abductor digiti minimi, Flexor digitorum brevis
  • 2nd layer: Flexor digitorum longus and flexor hallucis longus tendons, Flexor digitorum accessorius, and 4 lumbricals
  • 3rd layer: Flexor hallucis brevis, flexor digiti minimi brevis, adductor hallucis
  • 4th layer: Tibialis posterior, peroneus longus, 3 plantar and 4 dorsal interossei

Nerve Supply

• All muscles of the sole are innervated by the lateral plantar nerve, except for 4 muscles innervated by the medial plantar nerve (Abductor hallucis, Flexor digitorum brevis, Flexor hallucis brevis, 1st lumbrical)

Clinical Correlate (Pott Fracture)

• A Pott fracture involves the medial malleolus (transverse avulsion) and the fibula (oblique fracture) of the ankle joint, caused by the overly stretched medial (deltoid) ligament during extreme foot eversion.

Arches of the Foot

• The foot's bones form longitudinal and transverse arches
• These arches are vital for absorbing and distributing body weight during standing and movement
• The arches are supported by ligaments, including the spring ligament, short plantar ligament, and long plantar ligament, and the plantar aponeurosis.

Joints of the Foot

• Subtalar joint: A compound synovial joint comprising a posterior synovial plane joint (talocalcaneal) and an anterior synovial ball-and-socket joint (talocalcaneonavicular) strengthened by the plantar calcaneonavicular ("spring") ligament
• Mid-tarsal joints: Compound joint between the tarsal bones, including the calcaneocuboid and talonavicular joints. These joints enable inversion and eversion of the foot.

Explore the intricate structure of the foot and ankle in this quiz. Learn about the tarsal bones, metatarsals, and phalanges, as well as the ankle joint's function and supporting ligaments. A perfect resource for anyone studying human anatomy.