Tibialis posterior muscle
|Tibialis posterior muscle|
|The mucous sheaths of the tendons around the ankle. Medial aspect. (Tibialis posterior labeled at top center.)|
|Latin||musculus tibialis posterior|
|Gray's||subject #129 484|
|Insertion||navicular, medial cuneiform|
|Artery||posterior tibial artery|
|Actions||inversion of the foot, plantar flexion of the foot at the ankle|
|Antagonist||Tibialis anterior muscle|
It is the key stabilizing muscle of the lower leg.
Blood is supplied to the muscle by the posterior tibial artery, and innervation is via the tibial nerve.
Origin and insertion
The tendon of tibialis posterior muscle descends posterior to the medial malleolus and terminates by dividing into plantar, main, and recurrent components. The plantar portion inserts into the bases of the second, third and fourth metatarsals, the second and third cuneiforms and the cuboid. The main portion inserts into the tuberosity of the navicular and the plantar surface of the first cuneiform. The recurrent portion inserts into the sustentaculum tali of the calcaneus.
As well as being a key muscle and tendon for stabilization, the tibialis posterior also contracts to produce inversion and assists in the plantar flexion of the foot at the ankle. The tibialis posterior has a major role in supporting the medial arch of the foot. Dysfunction of the tibialis posterior, including rupture of the tibialis posterior tendon, can lead to flat feet in adults, as well as a valgus deformity due to unopposed eversion when inversion is lost.