ABSTRACT
This chapter provides an overview of the biomechanics of the foot and ankle as a basis for treating its disorders. The chapter is divided into three main sections: Biomechanics of the ankle; biomechanics of the midfoot and forefoot and the gait cycle. It also acts as a break between hindfoot and midfoot, allowing the hindfoot to rotate while the midfoot and forefoot remain stationary, and vice versa. The subsequent rupture of spring ligament and then failure of talonavicular joint results in collapse of the longitudinal arch and progressive abduction of the forefoot through transverse tarsal joint and progressive valgus deformity of the subtalar joint. The midfoot provides an important bridge between hindfoot and forefoot and gives flexibility for energy absorption and stability for push-off. Pronator and supinator twists occur only when transverse tarsal joint motion is inadequate to align the forefoot. The forefoot comprises metatarsophalangeal and interphalangeal joints.
