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