The Ankle and Foot Joints

Anatomy and Kinesiology

420:024

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

Gliding/nonaxial Intertarsal joints

Gliding/nonaxial Tarsometatarsal joints

Gliding/nonaxial

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) 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)

Abduction (intrinsic) 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)