The posterior tibial artery enters the foot through the tarsal tunnel on the medial side of the ankle and posterior to the medial malleolus. Midway between the medial malleolus and the heel, the pulse of the posterior tibial artery is palpable because here the artery is covered only by a thin layer of retinaculum, by superficial connective tissue, and by skin. Near this location, the posterior tibial artery bifurcates into a small medial plantar artery and a much larger lateral plantar artery.