Our research shows that habitually barefoot or minimally shod humans tend to walk and run differently than shod people, often in a way that leads to very low collision forces, even on very hard surfaces. How does the human foot work during walking and running without shoes? Humans have been walking and running for millions of years, and until recently we did so mostly barefoot or in very simple shoes such as sandals or moccasins. We have found and continue to study novel human features, from head to toe, that help humans be superlative endurance runners, including spring-like arches in the foot, short toes, long tendons in the legs, a large gluteus maximus, unusually large joints in the legs and spine, a nuchal ligament connecting the head and neck, low and wide shoulders that are decoupled from the head, an elaboration of sweat glands, and loss of body fur.įeet. When, how and why did humans become so exceptional as long distance endurance runners? My research with Dennis Bramble and other colleagues, suggests that long distance endurance running played a key role in the evolution of the genus Homo. When, how and why early hominins became bipeds? In collaboration with other researchers, I study early hominins such as Sahelanthropus and Australopithecus to understand how and why these hominins became bipeds, how they walked, ran and climbed, and how the evolution of human locomotion transformed the human body. To address these questions, I integrate three major lines of research: (1) experimental biomechanics and physiology in the lab, (2) fieldwork (mostly in Kenya and Mexico) to measure how people use their bodies in different cultures, and (3) analyses of the hominin fossil record in a comparative context. I am also interested in how that evolutionary history is relevant to preventing and treating diseases. I study how and why the human body is the way it is, especially the evolution of human physical activity.