Question

If you were to lose the function of the tibialis posterior, would foot inversion still be possible? 209 (12)

Answer 1

Before answering the question lets first look into the functions of tibialis posterior.

The Tibialis Posterior is the most central of all the leg muscles and is located deep inside the feet as shown in the figure below.

Lets study the main functions of the Tibialis posterior:

# It acts as a very important muscle and tendon for stabilization.

# It contracts to produce inversion (movement towards the midline of the body)

# It assists in the plantar flexion ( extension of the ankle so that the foot points down and away from leg)

# It plays a major role in supporting the medial arc of the foot (Allow the foot to support the weight of the body in erect posture )

Since tibialis posterior plays a major role in supporting the medial arch of the foot. Disfunction of the tibialis posterior including rupture of tibialis posterior tendon, can lead to flat feet in adults,impairing its ability to support the arch.It can even lead to valgus deformity ( a condition where the joint is angled outward away from the body's midline) due to unopposed eversion and loss of inversion. Inversion of the feet is not possible if the tibialis posterior tendon/muscle is lost.

Hope the answer was helpful. Thank you.