Abstract on windlass mechanics

It is during the action of dorsiflexion of the toes, which occurs in late stance phase that the plantar aponeurosis is stretched as it wraps around the metatarsal heads. This is the so-called windlass mechanism. Windlass is the tightening of a rope or cable (Viel and Esnault, 1989), which according to Hicks (1954) is like a triangular structure or truss, which occurs in the late phase of stance. This windlass is responsible for the stretch tension from the plantar fascia preventing the spreading of the calcaneus and the metatarsals and maintainsing the medial longitudinal arch (Fuller, 2000), which contributes to stiffening of the foot by pulling on the heel, causing inversion at the subtalar joint and `locking' the midtarsal joint (Briggs and Tansey, 2001). This occurs by shortening the distance between the calcaneus and metatarsals with the plantar fascia forming the tie-rod that runs from the calcaneus to the phalanges via the midtarsal joint, which carries as much as 14% of the total load on the foot whilst lowering the arch degenerates the load bearing capacity of the foot (Kim and  Voloshin,1985).