What is tarsal tunnel syndrome?

Tarsal tunnel syndrome is an entrapment of the posterior tibial nerve in the tarsal tunnel located on the inside aspect of the ankle. This can be caused by excessive foot pronation (rolling of the foot toward the body), overuse injury to the tendons that run through the tunnel, or trauma. Symptoms can include pain, numbness, and paresthesias (tingling) along the medial (inside) ankle and bottom of the foot.

Tarsal tunnel syndrome is a pinching of the tibial nerve, which stretches down the back of the leg to the inner ankle. In this area of the ankle, a complex mix of nerves, muscles, and ligaments meet; this makes the tibial nerve prone to entrapment, or pinching.

Symptoms of tarsal tunnel syndrome include foot pain and weakness as well as numbness and tingling in the sole or arch of the foot.

A nerve might get pinched as a result of:

• An injury to the ankle.
• Rolling the foot inward when walking or running (pronation).
• A tissue mass or cyst.
• An area of inflammation in or around a tendon (tenosynovitis).

At first, treatment may include rest, anti-inflammatory medicine, and supportive footwear, such as arch supports, custom orthotics, and support shoes. If this early treatment does not help relieve symptoms, surgery may be needed.

Tarsal tunnel syndrome results when the posterior tibial nerve is compressed within the tarsal tunnel. This condition is very similar, in mechanism, to carpal tunnel syndrome in the wrist. Both of these conditions result when a nerve is pinched within a confined space. The tarsal tunnel space is formed between bones and overlying fibrous tissue, which leaves it very little room to give when compressed. When the space becomes tight, the tibial nerve is pinched causing pain.