Many people experience pain in the arches of their feet and lower calves, oftentimes this can be linked to the often neglected tibialis posterior, an important muscle for the foot arch. So what is the tibialis posterior muscle?

What is the tibialis posterior and what does it do?

Tibialis posterior is a deep muscle along the back of our lower leg which extends into the bottom of our foot.This muscle has two main jobs; one, to help the foot move downwards and inwards, the second job, perhaps even more important is to help maintain the inside arch of our foot. Keeping our foot arched correctly is important not just for the foot but for all the muscles that attach around the foot as well as the joints above and below (i.e. the hip, knee and toes)

In the image, on the left side we can see the deep muscle compartment, here is where the tibialis posterior lies. Notice as it comes down the leg it runs under the foot by the inside arch.

On the right side of the illustration the superficial muscles are shown; in other words, the muscles that run on top of the tibialis posterior, the gastrocnemius predominantly.

How can this muscle be a source of my pain?

In some people, the tibialis muscle is elongated, meaning it’s overstretched (this could happen for a variety of reasons) as a result this can cause the inside arch of the foot to drop and the foot rolls in. This is not an ideal position for the tibialis posterior as it gets further stretched out, and alters the joint mechanics of the foot and hip and knee. This combination of the muscle being in an overly lengthened position as well as the altered joint mechanics can lead to pain, especially with impact activities.

Can I rehabilitate this muscle?

Yes! Strengthening the tibialis posterior muscle in a functional position can help, as well as mobilizing the joints of the foot, ankle and hip, all of which can be altered in alignment.

For those of us who over pronate when standing, a good exercise to strengthen the tibialis posterior is to stand with weight equally distributed over both feet and engage the tibialis posterior by producing an arch on the inside of your foot. The heel and the toes should all remain on the ground, and essentially you are drawing your big toe and heel toward one another, this is demonstrated in the pictures below.

In the first picture, we can see how the arch falls in and the effect this has on the knees is also evident, as they are falling in as result. In the second picture, the tibialis posterior is activated and we can see how the arch is improved and the knees are no longer falling in but rather into a neutral alignment.

Your physiotherapist can help direct the appropriate exercise program for tibialis posterior and affected joints.