Anatomy of the Ankle and Foot
The ankle mortise is made up of the distal tibia, fibula, talus (talocrural joint), subtalar joint (talus and calcaneus), talocalcaneonavicular joint, and calcaneocuboid joint. Ankle position can be affected by the ligamentous stability, musculotendinous lengths, and position of the bones and joints of the foot, such as the navicular height, medial arch height, tarsometatarsal joint, midtarsal joint, metatarsophalangeal (MTP) joint, and interphalangeal (IP) joint. The ankle and foot play a critical role in proprioception to maintain balance, especially during activities performed on uneven surfaces. During dynamic activities where the heel is off the ground (running, jumping, walking), the ankle can be vulnerable to strains and sprains because the base of support is smaller (just the ball of the foot instead of the entire plantar surface).