The upper part of the foot has occasionally been named the “saddle” as it is thought to resemble the back of the horse where the saddle might go. You can find a distinct deformity or bump that could develop on the upper surface of the feet, which is why this is occasionally termed a Saddle Bone. https://fitofithealth.com/saddle-bone-deformity-throw-the-kitchen-sink-at-it/