Tibialis Posterior Anatomy

The Tibialis Posterior is a spindle shaped long muscle of the calf group, present deep on the posterior aspect of the lower leg, in the posterior compartment (one of the four compartments of the lower leg). Of all the leg muscles, Tibialis posterior is the most centrally located muscle and plays a key role in the stabilization of lower leg.

Origin:

It originates from the medial (inner) side of posterior surfaces of tibia and fibula. A part of it also arises from the membrane present between tibia and fibula.

It runs vertically downwards along the posterior aspect of lower leg. It passes just behind the prominence on the inner side of ankle where it shifts its direction from vertical to horizontal.

Insertion:

Its lower most part (tendon) divides into three components, which insert into the heel bone, and tarsal and metatarsal (2nd, 3rd and 4th) bones of the foot.

Nerve supply:

Tibial nerve L5, S1

Blood supply:

Posterior tibial blood vessels

Movements:

It moves the foot downwards (plantarflexion) and twists it inwards (inversion).

Functions:

– It moves the foot inwards during walking.

– It stabilizes the medial side of ankle.

– The tendon of Tibialis posterior supports the arch of the foot. The dysfunction of Tibialis posterior tendon, results in a condition called acquired flat foot deformity, which results in pain and dysfunction of involved foot.

– It helps with the function of other muscles in the posterior compartment of leg.