The evolution and mechanics of the midfoot and hindfoot.

The foot and ankle have been an important part in the development of human gait and the erect posture of man. This paper presents several important evolutionary and biomechanical insights to the function of the midfoot and rearfoot. The bony architecture of the foot and ankle has enhanced the ability of man to walk in an upright posture. The complex movements of supination and pronation was established as a result of positional changes of the talus and calcaneus. The human foot has adapted to a bipedal striding gait by forming a compact structure that can absorb high ground reaction forces and provide a lever for push-off. Certain mechanical disorders of the foot and ankle may result from alterations of several evolutionary features. Excessive pronation and supination are the two major categories of mechanical disorders of the foot and ankle. The restoration of normal foot mechanics offers an important treatment approach to mechanical dysfunction of the foot and ankle.