Your shoes are changing your feet. The ankles (脚踝) of people who habitually wear shoes are different to those people who often walk barefoot. In many modern societies, people often wear shoes from a young age. However, many people around the world often go barefoot, or wear only very thin footwear.
"We know that there are some differences in the feet of modern humans, due to the use of shoes," says Rita Sorrentino at the University of Bologna in Italy. But most findings before related to the front and middle of the foot. She and her team have focused on the ankle instead. They studied 142 ankle bones from 1l populations from North America, Africa and Europe. These included sandal (草鞋) -wearing Nguni farmers in Africa, people living in New York and fossilized bones (骨骼化石) from Stone Age hunter-gatherers.
The hunter-gatherers' ankle bones were shorter than those people living in modern cities, and there were other differences in the shape. "They are mostly related to the behaviors of wearing and moving," says Sorrentino.
The hunter-gatherers walked barefoot for long distances every day over natural areas. Their ankles were relatively flexible (灵活的) ▲ , people who live in big cities, who wear narrow or small foot wear and walk short distances on flat roads, have more inflexible ankles.
It's believed that people have been wearing shoes for the past 10,000 years, says Sorrentino. For example, a sandal from a Missouri cave may be 8,300 years old. Early shoes were all fairly soft, so wouldn't have restricted the motion of the ankle much.
It is an open question if shoes have disadvantages, but Sorrentino thinks that modern shoes probably cause our bones to become weaker and easier to break.
