A burning, tingling or electric sensation travelling from the inside of the ankle into the sole of the foot is not something to simply push through. What is tarsal tunnel syndrome? It is a nerve compression condition that can make standing, walking, exercise and even wearing enclosed shoes increasingly uncomfortable. The symptoms can be subtle at first, which is one reason people may spend months treating it as a general foot ache before receiving an accurate assessment.
What is tarsal tunnel syndrome?
Tarsal tunnel syndrome occurs when the posterior tibial nerve, or one of its branches, is compressed or irritated as it passes through a narrow space on the inside of the ankle called the tarsal tunnel. This tunnel sits behind and below the bony prominence on the inner ankle. It is covered by a strong band of tissue called the flexor retinaculum and contains nerves, tendons and blood vessels travelling into the foot.
The posterior tibial nerve provides sensation to much of the sole and helps control small muscles in the foot. When pressure builds around this nerve, normal signals are disrupted. The result may be pain, pins and needles, numbness, burning or a feeling similar to an electric shock in the ankle, heel, arch or toes.
Tarsal tunnel syndrome is sometimes described as the foot and ankle equivalent of carpal tunnel syndrome in the wrist. The comparison is helpful, but the diagnosis is often more complex. There are several possible points where nerves can be compressed around the ankle and foot, and several other conditions can cause similar symptoms.
Symptoms that deserve assessment
Symptoms vary according to the location and severity of nerve irritation. Some people notice discomfort only after a long day on their feet. Others experience persistent pain at rest or symptoms that interrupt sleep.
Common features include burning or shooting pain along the inside of the ankle and into the sole, tingling or numbness in the heel, arch or toes, and pain that worsens with prolonged standing, walking or exercise. The foot may feel unusually sensitive to touch, or there may be an unpleasant hot, buzzing sensation inside the shoe.
In more advanced cases, weakness of the small muscles in the foot can occur. This may affect balance, toe control or the ability to push off comfortably while walking. Progressive numbness or weakness should be assessed rather than managed by changing footwear alone.
Symptoms are not always limited neatly to one area. That is why a careful history and examination matter. Heel pain from plantar fasciitis, a Morton’s neuroma, lower back nerve irritation, peripheral neuropathy and stress-related injuries can all be mistaken for tarsal tunnel syndrome, or may exist alongside it.
Why does tarsal tunnel syndrome develop?
Tarsal tunnel syndrome can arise from a clear structural cause, but not always. In some patients, a previous ankle injury or surgery leads to swelling, scar tissue or altered alignment around the tunnel. In others, the nerve is placed under ongoing tension because of the way the foot functions during walking.
Flat foot deformity is a significant consideration. When the arch progressively collapses and the heel rolls outward, the tissues on the inside of the ankle can be stretched or crowded. This may contribute to posterior tibial nerve irritation. Arthritis, bone spurs, ganglion cysts, varicose veins, tendon swelling and soft tissue masses can also occupy space within or near the tunnel.
Diabetes and other causes of peripheral neuropathy may make nerves more vulnerable to compression, although not every person with nerve symptoms has tarsal tunnel syndrome. Pregnancy-related swelling, inflammatory conditions and repetitive high-impact activity can also aggravate symptoms. The practical question is not simply whether the nerve hurts, but why it is under pressure in that particular foot.
How is tarsal tunnel syndrome diagnosed?
Diagnosis begins with listening carefully to the pattern of symptoms: where they start, where they travel, what brings them on and whether they occur at night or after activity. A specialist foot and ankle examination assesses sensation, muscle strength, foot posture, gait, ankle movement and areas of tenderness.
Tapping over the posterior tibial nerve may reproduce tingling into the foot. This is known as Tinel’s sign. It can support the diagnosis, but it is not definitive on its own. Nerve symptoms can fluctuate, and a normal examination on one day does not automatically rule out a compression problem.
Imaging may be recommended to identify contributing structural issues. Weight-bearing X-rays can show alignment, arthritis or bony changes. Ultrasound or MRI may help assess tendons, cysts, soft tissue swelling or a mass affecting the tunnel. Nerve conduction studies and electromyography can sometimes provide useful information about nerve function, although these tests do not detect every case.
A thorough assessment also considers the lower back, circulation and medical history. This prevents treatment being directed at the ankle when the source of symptoms lies elsewhere.
Treatment depends on the cause and severity
Early treatment generally aims to reduce pressure and irritation around the nerve while addressing any mechanical contributor. This may include activity modification, footwear changes, orthoses to support foot alignment, physiotherapy and anti-inflammatory measures where appropriate. A period of immobilisation in a walking boot may be considered when symptoms are aggravated by movement or associated tendon pathology.
The best non-surgical plan depends on the cause. For example, orthoses may be particularly useful where a flat foot is contributing to nerve tension, while a space-occupying cyst or significant bony prominence is less likely to resolve with footwear adjustments alone. Image-guided injections can be useful in selected circumstances, both diagnostically and therapeutically, but are not suitable for every patient.
Conservative care is often worthwhile, especially when symptoms are recent and there is no progressive weakness. However, ongoing numbness, worsening pain or reduced function despite appropriate management warrants specialist review. Nerves do not always recover predictably after prolonged compression, so delaying assessment for severe or progressive symptoms can affect the available treatment options.
When is surgery considered?
Surgery may be discussed when there is a defined compression source, persistent disabling symptoms despite appropriate non-surgical treatment, or evidence of progressive nerve dysfunction. The procedure is commonly called tarsal tunnel release or decompression. It involves carefully releasing the tight tissue over the tunnel and addressing the cause of compression where possible, such as scar tissue, a cyst, a bony prominence or associated structural deformity.
Surgery is not a one-size-fits-all answer. If painful flat foot or another alignment problem is placing ongoing tension on the nerve, a decompression alone may not fully address the underlying mechanics. In selected cases, reconstructive procedures may be considered as part of a broader treatment plan. The appropriate approach depends on examination findings, imaging, symptom duration, medical factors and the patient’s work and activity requirements.
As with any operation, there are risks, including wound healing issues, infection, persistent numbness, scar sensitivity, incomplete symptom relief and recurrence. Where nerve compression has been present for a long time, pain may improve before altered sensation does, and recovery can take months. A detailed surgical consultation should explain the likely benefits, limitations, recovery arrangements and expected time away from particular activities.
When to seek prompt medical advice
Arrange assessment promptly if you have new or worsening numbness, weakness, unexplained burning pain in the foot, or symptoms that are affecting sleep, work or safe walking. Urgent review is particularly important if sudden symptoms follow an injury, if there is marked swelling or colour change, or if you have diabetes and develop a new foot problem.
Persistent nerve pain is not simply a footwear problem to tolerate. A precise diagnosis can clarify whether the nerve is compressed, identify the structure contributing to it and help you make a considered decision about treatment. For patients whose mobility or quality of life is being limited, a specialist foot and ankle assessment provides a practical starting point for moving forward with confidence.