Study: Running Barefoot is Better
...the collision-free way that barefoot runners typically land is not only comfortable but may also help avoid some impact-related repetitive stress injuries. Kinematic and kinetic analyses show that modern shoes allow runners to land on the heel, as they do when they walk. Runners who don't wear shoes land more often on the ball of the foot or with a flat foot. This means that they often flex their ankles as they strike the ground and generate smaller impact forces than shod, rear-foot, strikers — compare the impact generated by landing from a jump on your heel versus your toes.