Tibialis Posterior: Foot and Ankle Muscle
The Tibialis Posterior is the lower leg’s deepest muscle (posterior compartment). This muscle and the tibialis posterior tendon are crucial to the stability of the foot’s medial arch. The Tibialis posterior is situated posterior to the interosseous membrane and deep to the large gastrocnemius and soleus muscles. This muscle travels across the ankle joint attaches to bones on the underside of the foot. This tendon acts like a suspension bridge to support the arch via the many attachments of the tibialis posterior tendon. If the tibialis posterior muscle and tendon become weak or damaged, the arch falls (flatfoot) and is called posterior tibialis tendon dysfunction (PTTD).