Tarsal Tunnel Syndrome: Symptoms and Treatment
Tarsal tunnel syndrome is compression of the posterior tibial nerve as it passes through a narrow channel behind the inner ankle — effectively the foot's version of carpal tunnel syndrome. It typically causes burning, tingling or numbness along the sole and inner ankle that worsens with activity. Most people improve with conservative treatment such as orthotics, rest and bracing, and surgery is reserved for cases that do not respond.
Anatomy of the tarsal tunnel
The tarsal tunnel is a narrow space on the inside of the ankle, just below the bony bump (the medial malleolus). It is roofed by a tough band of tissue called the flexor retinaculum. Running through this tunnel are tendons, blood vessels and the all-important posterior tibial nerve, which supplies sensation to much of the sole of the foot and powers some of the small foot muscles. According to OrthoInfo from the American Academy of Orthopaedic Surgeons, tarsal tunnel syndrome occurs when this nerve is squeezed or compressed within the tunnel — the same mechanism as carpal tunnel syndrome at the wrist, but at the ankle.
Because the tunnel is a confined, unyielding space, anything that takes up extra room inside it — swelling, a cyst, an enlarged vein or a bone spur — can press on the nerve and trigger symptoms. Understanding this helps explain both the symptoms and why treatment focuses on relieving pressure.
What causes tarsal tunnel syndrome
Often a specific cause can be identified, which is important because removing or treating it can resolve the problem. Common causes and risk factors include:
- Flat feet or fallen arches — when the arch collapses inward, the resulting strain and altered alignment can stretch and compress the nerve. See our flat feet guide and arch support guide.
- Space-occupying lesions such as a ganglion cyst, swollen (varicose) vein, lipoma or bone spur inside the tunnel.
- Injury — an ankle sprain or fracture can cause swelling or scarring that crowds the nerve.
- Systemic conditions — diabetes, arthritis and other inflammatory diseases can swell the tissues and make the nerve more vulnerable.
- Overuse or prolonged standing, especially in people who are on their feet all day or who have biomechanical imbalances.
Symptoms and signs
Symptoms follow the path of the posterior tibial nerve and usually affect the inner ankle and the sole of the foot. People commonly describe:
- Burning, tingling or an electric “pins and needles” feeling along the sole and inner ankle
- Numbness in the bottom of the foot, sometimes spreading toward the toes or heel
- A shooting or aching pain that is often worse with activity or prolonged standing and may ease with rest
- Symptoms that flare at night or after a long day on the feet
- In longer-standing cases, weakness of the small foot muscles
A useful clinical sign is the Tinel sign: gently tapping over the nerve behind the inner ankle reproduces tingling that shoots into the foot. If you have new numbness or burning in the feet, our overview of numb feet causes can help you compare possibilities — but persistent symptoms need a proper assessment.
How it is diagnosed
Diagnosis starts with a careful history and examination, including the Tinel test and a check of foot alignment, sensation and strength. To confirm nerve compression and rule out other nerve problems, a clinician may order nerve conduction studies and electromyography (EMG), which measure how well the nerve is transmitting signals. Imaging such as MRI or ultrasound is valuable when a space-occupying cause is suspected, as it can reveal a cyst, an enlarged vein, a bone spur or scar tissue inside the tunnel. Mayo Clinic notes that identifying a specific compressing structure often guides the most effective treatment. Because the symptoms overlap with other conditions, it is worth distinguishing tarsal tunnel syndrome from Morton's neuroma and from foot drop, which involve different nerves.
Conservative treatment
Most people are managed first without surgery, aiming to calm the nerve and relieve pressure. A clinician may recommend a combination of:
- Rest and activity modification to reduce repetitive strain on the nerve.
- Orthotics and arch support — particularly important when flat feet are driving the compression, as correcting alignment offloads the nerve.
- NSAIDs (non-steroidal anti-inflammatory drugs) to reduce pain and swelling, used as directed.
- Bracing or immobilisation — a brace or short period in a walking boot or cast can rest the area and let inflammation settle.
- Physical therapy for stretching, strengthening and nerve-gliding exercises, plus footwear advice.
- Ice and elevation after activity to control swelling around the tunnel.
The American Podiatric Medical Association emphasises that early treatment gives the best chance of avoiding permanent nerve damage, so persistent symptoms should not be ignored. If you are unsure whether your symptoms warrant a visit, see when to see a podiatrist.
Injections and surgery
If conservative measures do not bring enough relief, a clinician may try a corticosteroid injection to reduce inflammation and pressure on the nerve. When symptoms persist despite full non-surgical treatment, or when imaging shows a clear structural cause such as a cyst or spur, surgery (tarsal tunnel release) may be considered. The procedure opens the flexor retinaculum to decompress the nerve and removes any compressing structure. Outcomes are generally better when there is an identifiable cause and when surgery is done before long-standing nerve damage sets in. Recovery involves a period of protected weight-bearing and rehabilitation. As with any nerve surgery, results vary, and some numbness or tingling can persist, which is why surgery is a last resort rather than a first step.
Frequently asked questions
- Is tarsal tunnel syndrome like carpal tunnel of the foot?
- Yes. Tarsal tunnel syndrome is the foot and ankle equivalent of carpal tunnel syndrome. Instead of the median nerve at the wrist, it involves compression of the posterior tibial nerve as it passes through the tarsal tunnel behind the inner ankle bone.
- How is tarsal tunnel syndrome diagnosed?
- A clinician examines the inner ankle and taps over the nerve to check for tingling (a positive Tinel sign). Nerve conduction studies and electromyography help confirm nerve compression, while MRI or ultrasound can reveal a cyst, varicose vein or other space-occupying cause.
- Can tarsal tunnel syndrome be treated without surgery?
- Often, yes. Most people improve with conservative care such as rest, supportive orthotics, NSAIDs, bracing or immobilisation, and physical therapy. Steroid injections may help, and surgery to release the nerve is reserved for cases that do not respond to non-surgical treatment.
Sources & further reading
- Tarsal tunnel syndrome overview, American Academy of Orthopaedic Surgeons (AAOS)
- Nerve compression and foot pain, Mayo Clinic
- Foot and ankle conditions, American Podiatric Medical Association (APMA)
- Foot and ankle problems self-care, NHS