Tarsal Tunnel Syndrome (TTS) is also known as Posterior Tibial Nerve Neuralgia. TTS is a compression syndrome of the tibial nerve within the Tarsal Tunnel. In other words, it’s a collection of symptoms that occur because the nerve in this area is being irritated. It seems to affect both men and women equally and it can begin at any age.

This tunnel is found along the inner leg behind the medial malleolus (bump on the inside of the ankle). The posterior tibial nerve, a major artery, veins, and tendons travel in a bundle along this pathway, through the Tarsal Tunnel. In the tunnel, the nerve splits into three different paths. One nerve (calcaneal) continues to the heel, the other two (medial and lateral plantar nerves) continue on to the bottom of the foot. The Tarsal Tunnel is made up of bone on the inside and the flexor retinaculum (a tough band) on the outside.

Inflammation or swelling can occur within this tunnel for a number of reasons. The flexor retinaculum (that tough band on the outside) doesn’t stretch much, so increased pressure will eventually cause compression on the nerve within the tunnel. As pressure increases on the nerves, the blood flow decreases. Nerves respond with altered sensations like tingling and numbness. Fluid collects in the foot when standing and walking and this makes the condition worse. As small muscles lose their nerve supply they can create a cramping feeling.

- Painful/tingling in and around ankles – sometimes the toes

- Swelling of the feet

- Painful burning, tingling, or numb sensations in the lower legs

- The pain worsens and spreads after standing for long periods

- Pain is worse with activity and is relieved by rest

- Weakness

- Electric shock sensations

- Pain radiating up into the leg, and down into the arch, heel, and toes

- Pain can occur and persist at rest

- Typically the heels are spared (conflicting information on this)

- Hot/cold sensations in the feet

- Feeling as though the feet don’t have enough padding

- Pain while driving

- Throbbing

- Pain along the Posterior Tibial nerve path

- Burning sensation on the bottom of foot, radiating up

- Parasthesia (pins and needles)

- Dysaesthesia (abnormal pain)

- Hyperaesthesia (increased sensation)

- Tinel’s sign

This is a tingling electric shock sensation that occurs when you tap over an affected nerve. Your doctor may tap over the TT area to see if it elicits these shocks. The sensation usually travels into the foot but can also travel up the inner leg as well.

This is a list of symptoms that can occur with TTS, patients don’t necessarily have all of them. Only your doctor can determine whether or not you actually have this condition.

Often a doctor will arrive at a diagnosis based on the patient’s symptoms, and after ruling out other possibilities. There are many foot conditions that may have symptoms similar to those experienced with TTS. Your doctor will want to rule out things like plantar faciitis, stress fractures, or tendonitis. Sometimes these other foot problems can exist along with TTS.

Some systemic conditions can cause foot pain. Your doctor may order blood work including tests for low vitamin B12 (this can cause peripheral neuropathy), diabetes, thyroid, lupus, and rheumatoid arthritis. Along with a complete exam and history, the doctor may order x-rays and/or a bone scan or nerve conduction testing.

In some cases, a MRI is done to get a better look at what is happening in the tunnel, and to check for possible masses causing compression. Although an MRI isn’t really used to confirm a diagnosis of TTS, it can show other things that may be happening in the foot like tumors, stress fractures, or a ruptured tendon.

A neurologist usually administers nerve conduction tests. During this test, electrodes are placed at various spots along the nerves in the legs and feet. Both sensory and motor nerves are tested at different locations. Electrical impulses are sent through the nerve and the speed and intensity at which they travel is measured. If there is compression in the tunnel, this can be confirmed and pin pointed with this test. Many doctors do not feel that this test is necessarily a reliable way to rule out TTS. Some research indicates that nerve conduction tests will be normal in at least 50% of the cases. It is very possible to have TTS without a positive nerve conduction test. Many doctors feel that this test is unnecessary and often not helpful with diagnosis.

Whether or not it hurts seems to depend on a number of factors. There is a component to the test that isn’t always done – it involves inserting needles under the skin. The unanimous opinion (according to the people I’ve talked to) is that this portion of the test causes substantial pain. Ask your doctor if this part of the test will be required.

For the electrodes themselves, the degree of pain experienced seems to depend on the type of machine used (there are different kinds), the skill of the technician, as well as the stress and pain threshold level of the patient. Try to relax as much as possible during the test, and discuss any concerns you have with the technician or your doctor.

(Writer’s note: I’ve had this test twice on both my hands and feet – and I would describe it as mildly uncomfortable – not painful but I didn’t have the needles either).

It can be difficult to determine the exact cause of Tarsal Tunnel Syndrome, however it is still important to try to determine the source of the problem. Treatment and the potential outcome of the treatment may depend on the cause. Anything that creates pressure in the Tarsal Tunnel can cause TTS. This would include benign tumors or cysts, bone spurs, inflammation of the tendon sheath, nerve ganglions, or swelling from a broken or sprained ankle. Systemic conditions that may cause peripheral neuropathy (defined later) also make damage or irritation of the nerve more likely. These systemic conditions would include alcoholism, diabetes, rheumatoid arthritis, or thyroid disorders. Varicose veins (that may or may not be visible) can also cause compression of the nerve.

TTS can be due to a repetitive stress injury and it’s more common in athletes, active people, or individuals who stand a lot. These people put more stress on the tarsal tunnel area and it can make the tendon prone to swelling, and increase the likelihood of the nerve being stretched. Onset of TTS can also follow sudden activity in a previously inactive person.

People with flat feet may have increased pressure in the TT region and this can cause nerve compression. The short Achilles’ tendons that are seen with flat feet can cause more stress on the foot and the TT area.

Lower back problems can cause symptoms – specifically problems with the L4, L5 and S1 regions.

Don’t let this scare you too much. Peripheral means outer or surrounding, and neuropathy is basically a problem with the nerves. So, peripheral neuropathy is a problem with the outer nerves (like in the hands and feet). There are many different types of neuropathies, with carpal tunnel syndrome and tarsal tunnel syndrome being just two. Many different things including nutritional imbalances, drugs, or infection can cause neuropathies. In the case of TTS or CTS, the problem is caused by compression of the nerve. It is important for your doctor to determine what’s causing your symptoms. He/she will need to determine what is causing your neuropathy in order to know the best way to treat it.

Treatment options will depend on the cause of TTS. Systemic problems like arthritis, lupus, alcoholism or low thyroid need to be controlled. Your doctor will need to ensure that the symptoms are not being caused by lower back problems. Generally TTS treatment options will include the following: