The Ankle and Foot Joints Function of the

The Ankle and Foot Joints

Function of the foot • Provide a stable platform • Generate propulsion • Absorb shock

Bones • • Ankle + foot = 28 bones foot = 26 bones Leg: tibia, fibula Foot: – Tarsals (7): talus, calcaneus, navicular, cuboid, and cuneiforms (3) – Metatarsals (5) – Phalanges (14)

Joints • Tibiofibular: – articulation between tibia and fibula • amphiarthrodial joint • Ankle joint – Talocrural • articulation between talus and tibia; talus and fibula • classified as a ginglymus

Joints • Subtalar joint – articulation between talus and calcaneus – classified as arthrodial (gliding) joint • Transverse tarsal joint – articulation between talus, navicular, calcaneus and cuboid bones – classified as arthrodial joint

Joints • Tarsometatarsal – tarsal bones and metatarsal – classified as arthrodial (gliding) joints • Metatarsophalangeal – metatarsals and phalanges – classified as condyloid • Interphalangeal joints (proximal and distal) – phalangeal bones – ginglymus

Arches of the foot • Medial longitudinal arch – calcaneus, talus, navicular, cuneiforms (3), and medial metatarsals (3). • Lateral longitudinal arch – calcanueus, cuboid, lateral metatarsals (4 & 5) • Transverse arch – across metatarsals

Classifying Arch Type • Pes Planus: Flat foot • Pes Cavus: High Arch • Normal

Movements • Ankle joint – dorsiflexion: “raising the toes” – plantarflexion: “point the toes” • Subtalar & Transverse tarsal joints – Calcaneal inversion and eversion • Interphalangeal joints – flexion – extension

Movements • Supination • inversion • plantar flexion • adduction • Pronation • eversion • dorsiflexion • abduction

Summary • Bones of the foot: – tarsals, metatarsals, phalanges • Joints of the foot and ankle – – – talocrural (ankle) subtalar transverse tarsal metatarsalphalangeal interphalangeal • Movements – dorsiflexion/plantarflexion (ankle joint) – inversion/eversion (subtalar & transverse tarsal) – flexion and extension of toes about the interphalangeal joints

Muscles • • Plantar flexors Dorsi flexors Evertors Invertors

Plantar Flexors • • • Gastrocnemius Flexor digitorum longus Peroneus longus Plantaris Soleus Tibialis Posterior

Dorsiflexors • Tibialis anterior • Peroneus tertius • Extensor digitorum longus

Invertors • Tibialis anterior • Tibialis posterior • Flexor hallucis longus

Evertors • • Peroneus longus Peroneus brevis Peroneus tertius Extensor digitorum longus

Extensor digitorum longus (p 44) • Origin – lateral condyle of tibia – upper 3/4 of anterior aspect of fibula • Insertion – superior aspect of foot, middle and distal phalanges of four lesser toes • Action – Extension of four lesser toes – dorsal flexion – eversion

Extensor hallucis longus (p 45) • Origin – fibula, middle aspect of anterior fibula • Insertion – superior aspect of foot, base of distal phalanx of great toe • Action – dorsiflexion – extension of great toe

Peroneus tertius (p 46) • Origin – fibula, anterior-lateral surface of lower 1/3 of fibula • Insertion – superior aspect of foot, base of fifth metatarsal • Action – Eversion – Dorsal flexion

Tibialis anterior (p 47) • Origin – Lateral condyle of tibia – Upper two-thirds of anterior-lateral aspect of tibia • Insertion – plantar surface of 1 st (medial) cuneiform and 1 st metatarsal • Action – Dorsal flexion – inversion

Peroneus brevis (p 48) • Origin – fibula, lower two-thirds, lateral aspect • Insertion – 5 th metatarsal tuberosity • Action – eversion

Peroneus longus (p 49) • Origin – lateral surface of tibia – fibula, upper two-thirds of lateral aspect of fibula • Insertion – inferior aspect of foot, 1 st cuneiform and 1 st metatarsal bones • Action – Eversion – Plantar flexion

Flexor digitorum longus (p 50) • Origin – tibia, middle third, posterior aspect • Insertion – plantar surface of foot, distal phalanx of each of the four lesser toes (no big toe) • Action – ‘toe’ flexion – plantar flexion

Flexor hallucis longus (p 51) • Origin – fibula, lower two-thirds, posterior aspect • Insertion – plantar aspect of foot, base of distal phalanx of big toe (‘hallucis’) • Action – ‘big toe flexion’ – inversion

Gastrocnemius (p 52) • Origin – medial and lateral epicondyle of the femur • Insertion – posterior surface of calcaneus • Action – plantar flexion – knee flexion

Soleus (p 54) • Origin – upper 1/3 posterior shaft of fibula – posterior surface of head of fibula – popliteal line – middle 1/3 of medial border of tibia • Insertion – Posterior surface of the calcaneus • Action – Plantar flexion

Note • Gastrocnemius and Soleus muscles have a common tendon/insertion (calcaneal tendon or Achilles tendon) • Some texts refer to the combination of the gastrocnemius and soleus as the triceps surae (three headed muscle).

Plantaris (p 53) • Origin – posterior surface of lateral epicondyle of femur • Insertion – posterior surface of calcaneus • Action – plantar flexion

Tibialis Posterior (p 55) • Origin – middle 1/3 of posterior-lateral surface of tibia – middle 1/3 of posterior-medial surface of fibula • Insertion – plantar surface of foot, lower inner surfaces of navicular, cuneiforms, and 2 nd & 3 rd metatarsals • Action – plantar flexion – inversion

Summary of muscles • Plantar flexors – gast. , sol. , flx digitorum long. , per longus, tib post, plantaris • Dorsi flexors – tib ant, per tertius, ext dig long • Evertors – per longus, brevis, tertius, ext dig longus • Invertors – tib ant & post, flx hallucis long