Tarsal tunnel syndrome is a form of nerve entrapment in the ankle. This occurs when excessive pressure is placed on the posterior tibial nerve as it passes through a passage called the tarsal tunnel at the ankle. Excessive pressure causes the nerve to compress, leading to pain or other symptoms.
Some of the causes for the compression of this nerve include inflammation of surrounding tissues, crush or stretch injuries, fractures, dislocations of the ankle, and severe ankle sprains. This syndrome is akin to the more widely known carpal tunnel syndrome of the wrist.