Causes of Tarsal Tunnel Syndrome
Tarsal tunnel syndrome is most common in active adults, but it can also occur in children. Common symptoms, such as a burning or tingling sensation, result when the compressed tibial nerve attempts to send signals between the foot and brain.
An analogy can be made between the nerve and a garden hose. If a hose is drawn around a sharp corner, tension is created at the point of the bend. If the hose is pulled even tighter, it kinks and the flow of water through it is restricted. If the hose is stepped on, the flow is reduced even further.
In tarsal tunnel syndrome, the same types of forces are applied to the tibial nerve. When it is compressed by another structure, the neurological impulses through it are restricted. This causes pain, a burning sensation, and tingling. In many cases, the compression is caused by an adjacent muscle that grows too large for the area or from scar tissue that forms.
People with exceptionally flatfeet can develop tarsal tunnel syndrome because the flattened arch causes strain on the muscles and nerves around the ankle and changes their route slightly, producing compression on the tibial nerve.
In other cases, compression results from a cyst in this area. Systemic diseases such as rheumatoid arthritis and diabetes also can cause the syndrome.
Another common cause for tarsal tunnel syndrome is trauma to the ankle, such as a fracture. When the injury heals, fibrous tissue, similar to a scar develops. If too much scar tissue forms, it can restrict movement in the tarsal tunnel and cause entrapment of the nerve.