The tibialis posterior belongs to the semipinnatus muscle, which is located between the flexor digitorum longus and flexor digitorum longus in the deep posterior interspace of the calf, i.e., on the deep side of the calf triceps. It originates from the tibiofibular bone and the back of the interosseous membrane, and moves from 2/3 of the interosseous membrane of the calf and the tibiofibular bone to the long tendon, which is usually located at the back of the inner ankle, and can pass through the deep surface of the flexor support band to the medial edge of the foot, and ends at the tuberosity of the navicular bone and the basal plane of the three cuneiforms, and partly stops at the tuberosity of the navicular bone and divides into a number of thin tendons that travel under the navicular bone. The tibialis posterior muscle is innervated by the tibial nerve, which can contract to make the foot plantarflexed, externally rotated, and internally adducted. In addition, the tibialis posterior muscle belongs to the most powerful inversion muscle in the posterior group of muscles of the lower leg, which can maintain the stability of the longitudinal arch of the foot.