Function of Tibilias anterior скачать в хорошем качестве

Function of Tibilias anterior

The tibialis anterior muscle, also known as the tibialis anticus, is the largest of four muscles in the anterior compartment of the leg. Its thick muscle belly arises from its proximal attachment at the lateral tibia; the tibialis anterior tendon (TAT) inserts distally on the medial border of the foot. The muscle is primarily responsible for dorsiflexion and inversion of the foot.[1][2] Go to: Structure and Function Anatomy The tibialis anterior muscle, specifically its fleshy muscle belly, has a confluence of proximal attachments. These include the lateral condyle of the tibia, the proximal two-thirds of the lateral surface of the tibial shaft, the anterior surface of the interosseous membrane between the tibia and fibula, the deep surface of the fascia cruris, and the intermuscular septum between it and the extensor digitorum longus. The tibialis anterior tendon (TAT) begins at the distal one-third of the tibia. It travels across the anterior ankle and dorsum of the foot to insert vertically on the medial cuneiform and the base of the first metatarsal. It is the most medial tendon of the ankle and foot. The extensor retinaculum (ER), a transverse aponeurotic band comprised of superior and inferior components, covers the anterior ankle and foot. In most cases, the tibialis anterior tendon passes beneath the extensor retinaculum, so the extensor retinaculum holds the TAT in place. In 25% of cases, however, the superficial and deep layers of the superior extensor retinaculum form a separate tunnel for the tibialis anterior tendon. The synovial tendon sheath of the tibialis anterior tendon extends from above the superior extensor retinaculum, inferiorly to the level of the talonavicular joint. The main synovial bursa is between the tendon, the cuneometatarsal joint, and the medial cuneiform. Function The tibialis anterior (TA) is the strongest dorsiflexor of the foot. Dorsiflexion is critical to gait because this movement clears the foot off the ground during the swing phase.[3] The tibialis anterior, along with the tibialis posterior, is also a primary inverter of the foot. Because the TA arises from the lateral tibia and the tendon inserts on the medial border of the foot, muscle contraction lifts structures of the medial arch (medial cuneiform, first metatarsal, navicular, talus) into adduction-supination or inversion. The movement of inversion occurs at two synovial joints in the foot: the subtalar joint, between the talus and calcaneus, and the midtarsal joint, between the talus and navicular bone. The tibialis anterior is such a powerful inverter that muscles of the lateral compartment must be engaged in eversion for the TA to dorsiflex the foot without inversion. Due to its insertion on the medial foot, the tibialis anterior also supports the medial longitudinal arch of the foot. The medial arch is higher than the lateral arch and is formed by the following bones: calcaneus, talus, navicular, three cuneiforms, and the first three metatarsals.[4][5]