Tibialis posterior muscle

The Tibialis posterior is the most central of all the leg muscles.

It is the key stabilizing muscle of the lower leg.

Origin and insertion

It originates on the inner posterior borders of the tibia and fibula. It is also attached to the interosseous membrane, which attaches to the tibia and fibula.

The tendon of tibialis posterior descends posterior to the medial malleolus and to the plantar surface of the foot where it inserts on to the tuberosity of the navicular, the first and third cuneiforms, the cuboid and the second, third and fourth metatarsals.

Function

As well as being a key muscle for stabilization, the tibialis posterior muscle also contracts to produce inversion of the foot and assists in the plantar flexion of the foot at the ankle.

Additional images

Tibialis posterior also has a major role in supporting the medial arch of the foot and therefore dysfunction can lead to flat feet in adults (as well as unopposed eversion as inversion is lost, leading to a valgus deformity).

External links

• Diagram at washington.edu
• Diagram at latrobe.edu.au