Evolution of the Human Foot

Nature News has an interesting examination of how the human foot evolved the arch, the singular most important aspect in the ability to perform bipedal locomotion.  Glen Lichtwark and Luke Kelly write:

Humans evolved to walk and run effectively on the ground using two feet. Our arched foot, which is not a characteristic of other primates, is a unique feature crucial for human bipedalism. The arch provides the foot with the stiffness necessary to act as a lever that transmits the forces generated by leg muscles as they push against the ground. The arch also retains sufficient flexibility to function like a spring to store and then release mechanical energy. Writing in Nature, Venkadesan et al.1 present a new view of how foot stiffness is regulated. Their finding not only has exciting implications for understanding foot evolution, but also provides a possible framework when considering foot health and how to design better footwear.

The authors note that there are two different arches present in the human foot, the longitudinal arch, which is more familiar to people and the transverse arch. They argue that the transverse arch (across the top of the foot) is as important for walking as the longitudinal arch. The authors note that the transverse arch has been neglected in sports and medicine and that more research needs to be done in this area.