Tarsal Tunnel Syndrome

Tarsal tunnel syndrome (TTS) is a condition in which the tibial nerve in the ankle is compressed. This nerve allows feeling and movement to parts of the foot. Tarsal tunnel syndrome can lead to numbness, tingling, weakness or muscle damage, mainly in the bottom of the foot.

Tarsal tunnel syndrome is an unusual form of peripheral neuropathy that occurs when the tibial nerve is damaged. The tarsal tunnel is the narrow area in the foot where the nerve enters the back of the inner side of the ankle. When the tibial nerve is compressed, symptoms of tarsal tunnel syndrome occur.

Pressure on the tibial nerve may be due to any of the following:

• Swelling from an injury, such as a dislocated, sprained or broken ankle
• An abnormal growth, such as a bone spur, lump in the joint (ganglion cyst) or swollen (varicose) vein
• Flat feet or a high arch

Damage to the tibial nerve may result from body-wide (systemic) diseases, such as diabetes, low thyroid function (hypothyroidism), arthritis or hereditary nerve problems. In some cases, no cause of the damage can be found.

Tarsal tunnel syndrome more commonly affects women and athletes, as well as those who are overweight. The following conditions also increase the incidence of TTS:

• Tumors near the tibial nerve
• Varicose veins
• Bone spurs
• Nerve disorders
• Swollen tendons
• Lesions
• Arthritis and rheumatoid arthritis
• Diabetes
• Hypothyroidism
• Gout, mucopolysaccharidosis
• Hyperlipidemia
• Flat feet
• High arches
• Foot instability from overuse and injuries 
• Ankle sprains or fractures

Preventative measures include prioritizing proper foot care and health habits that reduce and minimize strain on the tibial nerve. Weight management, stretching, exercise, rest, supportive footwear and orthotics can all prevent TTS.

The first signs of TTS include pain inside your ankle or on the bottom of your feet. In severe cases, the foot muscles are very weak, and the foot can be deformed.

Additional symptoms of TTS may include any of the following:

• Sensation changes in the bottom of the foot and toes, including burning, numbness, tingling or other abnormal sensation
• Pain at the ankle and in the bottom of the foot and toes
• Weakness and atrophy of foot muscles that move toes

Your healthcare provider will examine your foot and ask about your symptoms. During the exam, your doctor may find you cannot curl the toes, push the foot down or twist the ankle inward and may be experiencing weakness of toe extension.

Some tests that may be performed for diagnosis include:

• Electromyography (EMG): a recording of electrical activity in muscles
• Nerve conduction tests: the recording of electrical activity along the nerve
• Imaging tests: X-rays, ultrasounds or magnetic resonance imaging (MRI)
• Blood tests: to look for medical conditions that lead to nerve damage

The treatment of TTS depends on the cause of the symptoms. Your provider will likely suggest resting, applying ice packs to the ankle and avoiding activities that cause symptoms. Over-the-counter pain medicine, such as nonsteroidal anti-inflammatory drugs (NSAIDs), may relieve any pain or swelling.

If your symptoms are caused by a foot problem, such as flat feet, custom orthotics or a brace may be prescribed, as well as physical therapy to strengthen the foot muscles and improve flexibility. Other treatments include steroid injections into the ankle. In more extreme cases of TTS, surgery may be suggested to enlarge the tarsal tunnel or transfer the nerve, which may help reduce pressure on the tibial nerve.

If the cause of tarsal tunnel syndrome is found and successfully treated, a full recovery is possible. Some people may experience partial or complete loss of movement or sensation, and nerve pain may be uncomfortable and long-lasting.

If left untreated, tarsal tunnel syndrome may lead to the following:

• Deformity of the foot (mild to severe)
• Movement loss in the toes (partial or complete)
• Repeated or unnoticed injury to the leg
• Sensation loss in the toes or foot (partial or complete)