The Ankle and Foot Joints Anatomy and Physiology of Human Movement 420:050

The Ankle and Foot Joints Must support entire body weight Over 100 ligaments Propulsion of entire body weight (F=ma) Very complex 26 bones ~25 joints 31 muscles 12 extrinsic muscles 19 intrinsic muscles

Objectives Bones, bony landmarks and joints Muscles Movements

Bones 29 bones, including tibia and fibula Calcaneus and talus Tarsals (5) Metatarsals (5) Numbered 1-5 Phalanges (14) Three for each toe Two for the big toe Big toes have sesamoid bones in metatarsophalangeal joint tendons

Ankle and Foot Joints Talocrural joint (ankle) Uniaxial hinge Subtalar joint Gliding/nonaxial Transverse tarsal joints Intertarsal joints Tarsometatarsal joints Metatarsophalangeal joints Biaxial ball and socket Proximal interphalangeal joints Little toes – Uniaxial hinge Distal interphalangeal joints Little toes – Uniaxial hinge Interphalangeal joint Big toe – Uniaxial hinge

Talocrural joint Subtalar joint Plantar/dorsiflexion Sagittal, ML axis Eversion/inversion Frontal plane AP axis

Objectives Bones, bony landmarks and joints Muscles Movements

Ankle and Foot Muscles Extrinsic muscles (12) Intrinsic muscles (19) Multiarticular (6) Knee/ankle (2) Ankle/toe (4) Uniarticular (6) Ankle (6) Intrinsic muscles (19)

Extrinsic Ankle and Foot (12) Knee and Ankle (2) Knee flexion, plantarflexion Ankle and Toe (4) Plantarflexion, toe flexion, inversion (2) Little toes Big toe Dorsiflexion, toe extension (2) Little toes, eversion Big toe, inversion Ankle (6) Plantarflexion (4) 2 invertors 3 evertors Dorsiflexion (2) 1 invertor 1 evertor

Objectives Bones, bony landmarks and joints Muscles Movements

Movements Plantarflexion (posterior compartment) Dorsiflexion (anterior compartment) Eversion (lateral compartment) Inversion (posterior and anterior compartment) Toe flexion (posterior compartment) Toe extension (anterior compartment) Toe abduction (intrinsic) Toe adduction (intrinsic)

Ankle Plantar Flexion Agonists Gastrocnemius Soleus Flexor digitorum longus Flexor hallucis longus Peroneus (fibularis) longus Peroneus (fibularis) brevis Plantaris Tibialis posterior

Ankle Dorsiflexion Agonists Tibialis anterior Extensor digitorum longus Peroneus (fibularis) tertius Extensor hallucis longus

Transverse Tarsal & Subtalar Inversion Agonists Tibialis anterior Tibialis posterior Flexor digitorum longus Flexor hallucis longus

Transverse Tarsal & Subtalar Eversion Agonists Peroneus (fibularis) longus Peroneus (fibularis) brevis Peroneus (fibularis) tertius Extensor digitorum longus

Toe Flexion Agonists Flexor hallucis longus Flexor digitorum longus

Toe Extension Agonists Extensor hallucis longus Extensor digitorum longus

Intrinsic Muscles (19)