The heel is the portion of the human body that lies at the bottom-rear part of each foot. Its exterior shape is formed by the calcaneus, also known as the heel bone. The heel bone is the largest bone in the foot.
The rear half of the heel bone is known as the tuber calcanei. It is responsible for the visible projection of the foot that constitutes the heel.
Two muscles of the foot, abductor hallucis and abductor digit minimi, extend from the heel bone's sides. These muscles move and flex the first (big) toe and the fifth toe, respectively.
The heel bone also contains the starting point of the Achilles tendon, which attaches the calf and its muscles to the heel.
The placement of the ankle and heel helps shape the area of the foot known as the arch. The arch and heel together allow the foot to evenly distribute any forces exerted on it, especially on ground that is not completely flat.