What is Tarsal Tunnel Syndrome?
Tarsal tunnel syndrome is an entrapment/compression neuropathy of the posterior tibial nerve. If you overpronate (your foot rolls in when you walk or run as shown) then pressure is put on these nerves which can become inflamed causing tarsal tunnel syndrome. Because the condition is often due to overpronation, it is common for bilateral tarsal tunnel syndrome to occur (i.e. in both feet!)
The term anterior tarsal tunnel syndrome is sometimes applied to a rare entrapment of the deep peroneal nerve at the front of the ankle, although this is not strictly the same as tarsal tunnel syndrome. Symptoms appear on the top of the foot and radiate towards the 1st and 2nd toes
What Causes it?
Tarsal tunnel syndrome can be both idiopathic - meaning it occurs spontaneously - or can be associated with a traumatic injury.
- Osteoarthritis at the ankle joint - possibly as a result of an old injury
- Rheumatoid arthritis
- Talonavicular coalition - fusing of two of the tarsal bones.
- A cyst or ganglion in the tarsal tunnel.
In people involved in running or running based sports, where the condition occurs spontaneously, then overpronation is the most frequent cause.
- Pain (often described as burning) radiating into the arch of the foot, heel and sometimes the toes.
- Pins and needles or numbness may be felt in the sole of the foot.
- Pain when running.
- Pain when standing for long periods of time.
- Pain is relieved by rest.
- Pain is often worst at night.
- Tapping the nerve (just behind the medial malleolus) may reproduce pain. This is known as Tinel's Test.
- The area under the medial malleolus may be tender to touch.
The symptoms of tarsal tunnel syndrome may initially be mistaken for plantar fasciitis which also causes pain from the medial heel and throughout the arch of the foot. Neural symptoms (such as tingling or numbness) as well as the location of tenderness when touching the area should help to easily distinguish between the conditions.
What can the athlete do about tarsal tunnel syndrome?
- Apply cold therapy in the acute (painful and inflamed) stage.
- Rest from any aggravating activities.
- Your Doctor may prescribe anti-inflammatory medication.
- See a sports injury professional who may prescribe a rehabilitation programme to ensure there is full movement and strength in the ankle.
- If the athlete is over pronating then they should see a specialist and have some orthotics fitted. You wouldn't build a house without getting the foundations right so why do it with your body?
- If this fails, a corticosteroid injection may be administered.
What might an injury specialist do?
- Nerve conduction studies may be undertaken to confirm the diagnosis and indicate the location of the entrapment.
- An X-ray or MRI may also be useful to determine the presence of any other structures such as cysts, arthritis or a tarsal coalition.
- If conservative treatment (see above) fails, then surgery may be required to decompress the nerve.
Tarsal Tunnel Syndrome Surgery
Surgery may be undertaken if conservative treatment has failed. The operation is undertaken to decompress the nerve by freeing the soft tissue structures in the area, creating more space for the nerve.
The success rate from tarsal tunnel syndrome surgery is mixed, with a high risk of complications. The procedure itself is very fast, although a complete recovery can take anywhere from a couple of weeks to a few months.