ANKLE JOINT
Definition
synovial joint between tibia, fibula, and talus
Location
Junction between leg and foot
Articulating Surfaces
Talus Distal tibia & fibula Covered with hyaline cartilage
Structure
Talus sits in mortise formed by tibia and fibula Joint capsule surrounds joint and is lined by synovial membrane
Ligaments of Ankle Joint
Medial (deltoid) ligament Anterior talofibular ligament → lateral Posterior talofibular ligament → lateral Calcaneofibular ligament → lateral
Nerve Supply
Deep peroneal nerve → anterior Tibial nerve → posterior Sural nerve → lateral
Blood Supply
Anterior tibial artery Posterior tibial artery Peroneal artery
Movements
Dorsiflexion, plantarflexion Inversion, eversion (subtalar joint)
Muscle Action Sequence
Dorsiflexion → tibialis anterior Plantarflexion → gastrocnemius, soleus Inversion → tibialis anterior & posterior Eversion → peroneus longus & brevis
Stepwise Anatomical Mechanism
Dorsiflexion: tibialis anterior contracts → foot moves upward Plantarflexion: gastrocnemius & soleus contract → foot moves downward
Clinical Anatomy
Ankle sprain → lateral ligaments commonly injured Fracture-dislocation → risk to neurovascular structures Achilles tendon rupture → plantarflexion affected