ConditionBones, joints & muscles
Tarsal Tunnel Syndrome
Tarsal tunnel syndrome is compression of the posterior tibial nerve as it passes through a narrow channel on the inner side of the ankle, behind the ankle bone. It causes burning, tingling, shooting pain or numbness in the sole of the foot, heel and toes, often worse with standing, walking or at night. It is sometimes called the "carpal tunnel of the foot". Causes include flat feet, ankle injuries, swelling, cysts and varicose veins. Supportive footwear, orthotics and anti-inflammatory measures help most people.
Also called: Posterior tibial nerve compression, tibial nerve entrapment, posterior tibial neuralgia
At a glance
- What it is
- Compression of the posterior tibial nerve in the tarsal tunnel at the inner ankle.
- Symptoms
- Burning, tingling, electric or shooting pain and numbness in the sole, heel and toes.
- Pattern
- Worse after standing, walking or exercise, and often at night.
- Causes
- Flat feet, ankle injuries, swelling, ganglion cysts, varicose veins, bone spurs, diabetes, arthritis.
- Diagnosis
- Examination with Tinel's sign, nerve conduction studies, ultrasound or MRI.
- Treatment
- Rest, orthotics, supportive shoes, anti-inflammatories, injections, and surgery for persistent cases.
When to get help
See a doctor within a day or two
- Sudden numbness and weakness in the foot after an ankle injury
- Rapidly worsening foot weakness or loss of sensation
- A swollen, red, hot foot or ankle, especially with diabetes
Book a routine appointment
- Burning, tingling or numbness in the sole of the foot lasting more than a few weeks
- Foot pain that wakes you at night
- A lump on the inner ankle with tingling in the foot
- Numbness in both feet, especially with diabetes (possible peripheral neuropathy)
Usually safe to manage at home
- Mild, occasional tingling after a long day on your feet that improves with rest and supportive shoes
Anatomy of the tarsal tunnel
The tarsal tunnel lies on the inner side of the ankle, below and behind the medial malleolus (the inner ankle bone), covered by a thick band of tissue called the flexor retinaculum. Through it pass the posterior tibial nerve, artery and veins, and three tendons. The nerve then divides into branches supplying the sole and heel. Anything that narrows the tunnel or swells its contents can compress the nerve.
Causes and risk factors
- Flat feet or overpronation, which stretches and compresses the nerve
- Ankle sprains and fractures, causing swelling or scar tissue. See ankle sprain
- Space-occupying lesions: ganglion cysts, lipomas, nerve tumors, bone spurs
- Varicose veins in the tunnel
- Tendon inflammation, including posterior tibial tendon dysfunction
- Systemic conditions: diabetes, rheumatoid arthritis, hypothyroidism
- Swelling from pregnancy, heart, kidney or venous problems
- Repetitive stress from running or prolonged standing
In many cases, no specific cause is found.
Symptoms
- Burning, tingling or "pins and needles" in the sole, heel or toes
- Shooting or electric-shock pain
- Numbness
- Pain on the inner ankle
- Symptoms worse with standing, walking, running or at night
- Symptoms that may spread up the calf
- In long-standing cases, weakness of small foot muscles
Tarsal tunnel syndrome vs other causes of foot pain
| Condition | Clues |
|---|---|
| Tarsal tunnel syndrome | Burning, tingling and numbness in the sole, positive tapping over the inner ankle |
| Plantar fasciitis | Sharp heel pain with the first steps in the morning, no numbness |
| Peripheral neuropathy | Both feet, glove-and-stocking pattern, often with diabetes |
| Morton's neuroma | Burning between the third and fourth toes |
| Lumbar radiculopathy (S1) | Back pain, pain down the back of the leg, reduced ankle reflex |
Tarsal tunnel syndrome and plantar fasciitis can occur together.
Diagnosis
- Examination: tapping over the nerve behind the inner ankle may reproduce tingling (Tinel's sign). Holding the ankle turned outward and the toes pulled up may also provoke symptoms. The doctor checks foot posture, sensation and strength.
- Nerve conduction studies and EMG: measure nerve function, though results can be normal in mild cases.
- Ultrasound or MRI: to look for cysts, tumors, varicose veins, tendon problems or bone spurs.
- Blood tests for diabetes, thyroid problems and other causes of neuropathy.
Treatment
Non-surgical treatment
- Rest from activities that worsen symptoms
- Ice to reduce inflammation
- Supportive shoes with good arch support
- Custom or over-the-counter orthotics to correct flat feet and overpronation
- Ankle brace or night splint to limit movement that compresses the nerve
- NSAIDs such as ibuprofen at label doses, if safe for you
- Physical therapy: nerve gliding exercises, calf and foot stretching, strengthening
- Corticosteroid injection into the tunnel to reduce swelling
- Nerve pain medicines such as gabapentin, pregabalin or duloxetine for persistent burning pain
- Treating underlying conditions such as diabetes or arthritis
Surgery
Tarsal tunnel release is considered when symptoms persist after several months of conservative treatment, or when a cyst, tumor or other mass is compressing the nerve. The surgeon cuts the flexor retinaculum to create more space and removes any compressing lesion. Results are better when a specific cause is found and symptoms have not been present for very long. Recovery takes several weeks to months.
Outlook
Many people improve with conservative treatment. Surgery helps most patients with a clear compressive cause, although results are less predictable than carpal tunnel surgery. Long-standing compression can cause permanent numbness or weakness, so early treatment is beneficial.
Frequently asked questions
What are the symptoms of tarsal tunnel syndrome?
Symptoms include burning, tingling, shooting pain and numbness in the sole of the foot, heel and toes, often with pain at the inner ankle. Symptoms are usually worse after standing or walking and may be worse at night.
What causes tarsal tunnel syndrome?
It is caused by anything that compresses the posterior tibial nerve at the inner ankle, such as flat feet, ankle injuries, swelling, ganglion cysts, varicose veins, bone spurs or inflamed tendons. Diabetes and arthritis increase the risk.
How is tarsal tunnel syndrome treated?
Most people are treated with rest, supportive shoes, orthotics, ice, anti-inflammatory medicines, physical therapy and sometimes steroid injections or nerve pain medicines. Surgery to release the nerve is used if symptoms persist or a mass is pressing on it.
How is tarsal tunnel syndrome different from plantar fasciitis?
Plantar fasciitis causes sharp heel pain, especially with the first steps in the morning, without numbness. Tarsal tunnel syndrome causes burning, tingling and numbness in the sole and toes from nerve compression. They can occur together.
Can tarsal tunnel syndrome go away on its own?
Mild cases caused by temporary swelling or overuse may improve with rest and better footwear. Persistent cases usually need treatment, and long-standing compression can cause lasting nerve damage, so see a doctor if symptoms continue.
Sources
This guide was written from current patient and clinical guidance, including:
- American College of Foot and Ankle Surgeons (FootHealthFacts): Tarsal tunnel syndrome
- American Academy of Orthopaedic Surgeons (OrthoInfo): Tarsal tunnel syndrome
- American Podiatric Medical Association: Nerve problems of the foot
- MedlinePlus: Tibial nerve dysfunction
- American Academy of Family Physicians: Diagnosis of heel pain