During walking, the center of body mass must pass from behind the weightbearing foot to in front of it. For this to take place, the foot must function as a sagittal plane pivot. Because the range required for this motion is approximately five times as great as both frontal and transverse plane motion, its evaluation should become an essential part of a podiatric biomechanical assessment. Lack of proper sagittal plane motion and its sequelae are described.