For about 80 years at least, scientists have been under the impression that human feet are special. Studies comparing human and chimpanzee footprints in the 1930s suggested that human feet were much stiffer than those of other apes. Humans have arches in the mid-foot region, as well as rigid outer edges, leading scientists to conclude that our mid-foot regions weren’t capable of touching the ground, unlike those of our ape relatives.
More recent evidence has suggested the contrary. Studies that measured foot mechanics with machines have hinted that some people’s arches often make contact with the ground as they walk. However, these machines were able to measure only a few footsteps at a time.
Thanks to a pressure-sensitive treadmill, researchers at the University of Liverpool were able to examine 25,000 footsteps made by 45 healthy human volunteers. About two-thirds of those volunteers took some steps in which their mid-foot touched the ground,