As we are still in Foot Health Awareness Month, we are featuring another foot deformity, caused by overuse. The posterior tibial tendon is a little-known, but hugely important anatomical structure along the inside of your ankle. The tendon itself is not much thicker than a pencil, but it plays an essential role in foot stabilization.

The posterior tibial tendon runs into your foot along your instep, beside the medial malleolus, the large bump on the inside of your ankle, and attaches to the tibialis posterior muscle, which is buried deep inside your calves.

By applying tension along the inside of your ankle, the tibialis posterior muscle and the posterior tibial tendon play a critical role in maintaining the arch and support of your foot.

Any time you run or walk, your posterior tibial tendon locks your ankle in place, helping to hold your foot in a strong, rigid configuration when you push off the ground. It also functions to invert your foot, rolling your ankle to shift your weight to the outside of your foot.

If the arch of your foot is like a suspension bridge, the posterior tibial tendon is the huge steel cable that provides the tension to support it. Without a strong, properly functioning posterior tibial tendon, your arch can’t stay up, your ankle can’t stay locked, and your calves can’t leverage their strength across the joints in your foot.

Do I have Posterior Tibialis Dysfunction?

The hallmark sign of posterior tibial tendon dysfunction is localized pain along the inside of your foot and ankle, sometimes stretching into your shin. There might be some mild swelling around the tendon, and the area might be tender or painful if you push it. You may experience pain when you try to activate your posterior tibial tendon by lifting the inside of your foot off the ground.

Though it’s not a well-known running injury— actually only the 26th most common running injury, according to one study1—posterior tibial tendon dysfunction (sometimes also called posterior tibial tendonitis) can be extremely challenging to “fix.”

Worse, if not addressed, it has the tendency to become progressively worse over time. In some cases, it can become so severe that your foot’s arch collapses, leaving you with a permanently flat foot. As posterior tibial tendon dysfunction worsens, your arch height drops and your foot becomes more pronated when you put weight on it because the tendon can no longer provide adequate support.

As a result, the tension on the posterior tibial tendon increases. This creates a vicious cycle where a lower arch and increased pronation increase stress on the posterior tibial tendon, which in turn sustains more damage, leading to even greater arch collapse and pronation, and the cycle starts again.2

How can I treat Posterior Tibialis Dysfunction?

Foot orthotics can provide extra arch support, which reduces the demands on the posterior tibial tendon. When paired with the correct fitting shoe and proper compression (due to swelling at the inside of the ankle and foot), extra support is thus given.

At medi, the medi protect foot support active is a great insole for the initial stages of PTTD, as it can provide more stability and higher levels of control needed in the foot. It can also be heat-molded and customized to a patient’s foot to ensure proper alignment and fit. It’s a great option for those with generally flatter feet.

If the stage is more severe, though, the medi foot support junior is a great option as it provides optimal foot stability. It has a high medial phalange that supports the medial longitudinal arch and a high lateral phalange that supports the lateral longitudinal arch. In addition, a deep heel cup ensures proper alignment from the heel to the toe. It ranges in size all the way from child to adult. It is imperative that action be taken once pain develops, as back, hip and even knee pain can start. If the tendon collapses, it can lead to many other joint and muscle dysfunction.

1.Taunton, J.; Ryan, M.; Clement, D.; McKenzie, D.; Lloyd-Smith, D.; Zumbo, B., A retrospective case-control analysis of 2002 running injuries. British Journal of Sports Medicine 2002, 36, 95-101.

2.Rabbito, M.; Pohl, M. B.; Humble, N.; Ferber, R., Biomechanical and Clinical Factors Related to Stage I Posterior Tibial Tendon Dysfunction. Journal of Orthopaedic & Sports Physical Therapy 2011, 41 (10), 776-784.