The posterior tibial refers to a key artery in the leg that supplies blood to the lower leg and foot. It branches off from the popliteal artery, which is located behind the knee. The posterior tibial artery runs down the back of the leg and divides into smaller arteries that provide oxygen-rich blood to the muscles and tissues of the foot. In addition to the artery, the term posterior tibial can also refer to the posterior tibial nerve, which runs alongside the artery. This nerve is responsible for sensation and movement in parts of the foot. Both the artery and nerve are crucial for maintaining proper function and circulation in the lower extremities.