We equipped an insole with a force sensor that can detect in real time when a foot over pronates. When such behavior is detected, we warn the user so they can correct their posture by using their own muscles. The effectiveness of this novel way to correct over pronation posture is evaluated over a two-week period. The use of vibrotactile feedback reduces over pronation by 30% to 50% during the first week. The natural benefits of the proposed method vs. use of passive orthotics are also presented.