From Here

It's really a case for minimal footwear, Daniel Lieberman says: "For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes."
Stringer explains that the degree of robustness in toe bones allows experts to distinguish from the condition of skeletal material whether people wore shoes or went barefoot during their lives. Skeletons from 40,000 years ago at Tianyuan, China, and also 28,000 years ago from Sungir, Russia, clearly bear on their bones the marks of shoe-wearing.