The Ankle and Foot Joints Anatomy and Physiology

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

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

Objectives l l l Bones, bony landmarks and joints Muscles Movements

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

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

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

Objectives l l l Bones, bony landmarks and joints Muscles Movements

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

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

Objectives l l l Bones, bony landmarks and joints Muscles Movements

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

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

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

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

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

Toe Flexion l Agonists l l Flexor hallucis longus Flexor digitorum longus

Toe Extension l Agonists l l Extensor hallucis longus Extensor digitorum longus

Intrinsic Muscles (19)