Definition: “Tibial Nerve” one of the two major divisions of the sciatic nerve, it courses down the back of the leg to terminate as the medial and lateral plantar nerves in the foot; it supplies the hamstring muscles, the muscles of the back of the leg (the dorsiflexors and invertors of the foot), and the plantar aspect of the foot, as well as the skin on the back of the leg and sole of the foot. Provided by Medilexicon
The Tibial Nerve courses down the inner ankle in a space referred to as the “Tarsal Tunnel” The tarsal tunnel is protected and covered by a thick ligament called the flexor retinaculum. The Tibial Nerve is called the “Posterior Tibial Nerve” as it enters the ankle and is the largest nerve to serve the foot. Most sensations felt in the bottom of the foot are from the Posterior Tibial Nerve. There are also tendons and blood vessels that travel through the Tarsal Tunnel. Tarsal Tunnel Syndrome (TTS) is the same as Carpal Tunnel Syndrome of the wrist. In that both cases a nerve is pinched or compressed in some manner or form.
Tarsal tunnel syndrome happens when the Posterior Tibial Nerve is compressed within the Tarsal Tunnel.
- Flat Footed feet are prone to developing Tarsal Tunnel Syndrome (TTS). A flat foot leans inward toward the inner ankle, therefore more pressure is applied to the tarsal tunnel.
- Any type of swelling or inflammation in the ankle or foot can compress the nerve. Examples: Sprained Ankle, diabetes, water retention in the foot, arthritis, swollen tendon, etc.
- Any type of abnormal growth that invades the space within the tarsal tunnel. Examples: Cyst, bone spur, Varicose Vein, etc.
Common Symptoms of TTS:
- The pain can radiate from the ankle up but most likely from the ankle downward and into the foot. Most cases report pain in the bottom of the foot towards the outside portion. This may include a burning, numbness, tingling or shooting pain.
- Pain typically increases when pressure is applied from prolonged usage such as standing or walking.
- Tarsal Tunnel Syndrome is often mistaken for Plantar Fasciitis, we will discuss this later.
A Few Things You Can Do To Self-Diagnose.
- There are a few telltale signs and steps that you can perform yourself.
- Are you flat footed and over pronate when you walk:
- Has the Pain began suddenly or gradually? Either may occur, but gradually is a telltale sign.
- Try to duplicate the shooting and tingling sensation by tapping lightly on the Tibial Nerve. This method is called Tinel’s Sign. Tap on the nerve with a finger and if pain shoots or a tingling sensation (often referred to as: Pins and Needles) is felt, then this is a sure sign that TTS is present and not Plantar Fasciitis. Pins and Needles is a sign of nerve pain, Plantar Fasciitis is not nerve pain.
- Do you see swelling in the ankle area? If so this is a sign of increased pressure on the Tarsal Tunnel area.
- Having diabetic neuropathy or poor circulation can both cause burning and tingling in the feet and be mistaken for TTS.
Treatment for TTS.
- Conservative treatment starts with reducing the swelling, this includes icing, elevating the foot, immobilizing the foot by using a walking cast, Taking Ibuprofen or Aleve. Corticosteroid shots may be prescribed by the physician.
- Changing the walking gait is most often recommended by using a custom orthotic. This will relieve the excessive pressures from being flat footed and over pronating.
When Surgery Is Required
As mentioned above, sometimes there is an obstruction in the Tarsal Tunnel that must be removed surgically. This surgery is referred to as “Nerve decompression”. Most physicians will still recommend the use of orthotics after surgery, especially if the patient is flat footed.