I mentioned that a sprain occurs to a ligament. Valgus feet is a condition where the feet collapse and the ankle bones internally rotate. When viewed from the rear, you will see that, in effect, the ankle does not rest directly above the feet. Such a structure increases the stress on the ligaments, a stress that increases significantly in physical fitness and athletic fitness activities. Consider, for example, that if an athlete jumps 12 inches off the floor, it’s estimated that the force upon landing is five times greater than bodyweight. This could explain why 46 percent of the injuries to the basketball players in the Australian study occurred during landing.