The posterior tibial tendon is one of the most important supporting structures of the foot. It helps to stabilize the ankle and hold up the arch. If the posterior tibial tendon fails, the arch can collapse, leading to foot pain, ankle pain and difficulty walking. Posterior tibial tendonitis is a frequent cause of pain at the inside of the ankle.
An ankle sprain is an injury to one or more ligaments in the ankle,usually on the outside of the ankle. Ligaments are bands of tissue—like rubber bands—that connect one bone to another and bind the joints together. In the ankle joint,ligaments provide stability by limiting side-to-side movement.
The tarsal tunnel is a narrow space that lies on the inside of the ankle next to the ankle bones. The tunnel is covered with a thick ligament (the flexor retinaculum) that protects and maintains the structures contained within the tunnel—arteries,veins,tendons,and nerves.One of these structures is the posterior tibial nerve,which is the focus of tarsal tunnel syndrome.