A common command or recommendation is to use the feet to move faster when attempting to execute a skill. You can hear it given in almost every sport even in golf, in order to deliver more power. It seems to be a universally accepted fact that faster feet improve performance.
But can you affect what happens in execution of a skill simply by doing something with the feet? If you seriously consider this you will see that movement of the feet (without any prior actions) cannot by themselves do anything in skill execution.
Because of this it is surprising to see so many articles related to foot and ankle actions as being the causative action for what happens in execution of a sports skill. For example, coaches talk about foot actions most often as causing the body to run or cut faster or as a means of getting more power in the hit.
However, from an anatomical and biomechanical perspective, this cannot happen if the body is balanced on both legs! The only thing the feet can do is raise the body directly upward via ankle joint extension. No other action of the ankle joint (feet) will cause the body to move in any direction when the weight is balanced over the feet.
The feet, however, can react to changes in body positions. Because of this it is more accurate to say that the feet respond to the actions of the hips or upper body during a swing, run or cut. In other words, it is not the feet that do the action but the body actions that determine the position of the feet throughout the execution.
The feet adjust according to what happens above the ankle joint. The ankle or foot actions are a consequence of a joint action above the feet (knee, hip, upper body actions) but they are not the cause of the action.
You cannot move the feet (or even roll them) during a swing or run to create movement of the upper body (except upward) if weight is over both feet. The feet however, will respond to a shift in body weight or more precisely, movement of the hips over one leg.
The unweighted foot will appear to roll inward or outward in a sideward move, but it is merely being rotated because of the weight shift to the other leg. The weighted foot will be flat on the ground or turned slightly inward if the weight goes beyond the forward edge of the hips.
You can prove it very easily to yourself by assuming a balanced stance and then, without shifting your weight, try turning your feet inward or outward. Do not make any movements of the upper body. You will see that you can’t roll the feet without prior movement of the knees, hips, or upper body. If you plantar flex the ankles (ankle extension) your body will only rise upward.
Thus, if you concentrate on the foot action it only leads to a disrupted swing or movement. The feet naturally respond to what happens above, especially to weight shift, in order to keep you in balance and stable. It is a consequence of what you do in execution of the skill; it is not a causative factor.
The foot or ankle action however, is extremely important in producing greater speed and force in movements where the body is already in front of or behind the foot. In this way he can move the body (or hips) in the intended direction.