Tarsal tunnel syndrome

What is tarsal tunnel syndrome, and how common is it?

Tarsal tunnel syndrome is a squeezing of the posterior tibial nerve as it passes under a tough band of tissue on the inside of your ankle¹. This nerve runs down the back of your leg and into your foot². It's often compared to carpal tunnel syndrome in the wrist³.

It's less common than other nerve compression problems, and it's often overlooked or mistaken for plantar fasciitis (a common cause of heel and sole pain)². Because it's so often missed, it's probably more common than the numbers suggest. A health professional needs to make the diagnosis.

What causes it, and who gets it?

Often no cause is found. Most cases are described as idiopathic (no clear cause)³. When there is a cause, it's usually local: a bone spur, a cyst, varicose veins, tendon inflammation, scarring or a past injury⁴. Rarely, an extra (accessory) muscle is responsible⁵.

Conditions linked with it include diabetes, rheumatoid arthritis, an underactive thyroid and pregnancy³. Foot deformities and obesity are also named². Runners may be more likely to get it, especially if the foot rolls inward⁶.

These are links, not proven causes. A lump or cyst can sometimes be behind it, so it's worth having symptoms assessed rather than assuming overuse. Tell your clinician about any past ankle injury or surgery, diabetes, arthritis, thyroid problems, swelling and how much you run.

What does it feel like, and how is it diagnosed?

It typically causes burning pain, numbness and tingling in the sole, heel and inner ankle, sometimes reaching the inner foot and first three toes⁴². Symptoms often get worse with standing, walking or activity, and at night, and ease when you rest with your foot up⁶².

No single test confirms it. A clinician works from your symptoms and an examination, and a nerve test called Tinel's sign is the one most often used⁷. Because there's no standard approach, practice varies⁷. A scan such as an MRI may be used if a lump is suspected⁴.

A pinched nerve in the lower back can feel similar, though it usually affects one side. If both feet are affected, a wider nerve problem (polyneuropathy) should be ruled out⁶. If you have diabetes with existing nerve damage, tarsal tunnel syndrome is harder to pick out, and test results need careful interpretation⁷.

What helps first?

Start with simple care, ideally guided by a podiatrist or physiotherapist. Treatment usually begins with easing the activities that bring symptoms on, stretching, massage, taping and, for some people, medicines for nerve pain⁷. Calf stretching, nerve gliding (gentle exercises that move the nerve through its tunnel), strengthening the muscle behind the inner ankle and a wedge under the inner edge of the heel are also described. Simple care is often enough⁶. A podiatrist can tell you whether a heel wedge or shoe inserts suit you.

How much each step helps isn't clear yet, and some people treated for it may turn out to have another condition⁷. If you're not improving, ask for a review.

For pain relief, a GP or pharmacist can advise what's safe for you. Paracetamol and anti-inflammatory medicines are among those listed⁶. Avoid ice packs if you're sensitive to cold, have an open wound, poor circulation or reduced feeling of hot and cold⁸.

What helps if that isn't enough?

First, ask for the diagnosis to be confirmed, since other conditions can look like tarsal tunnel syndrome⁶.

If simple care hasn't helped, or a structural cause such as a lump is found, surgery to free the nerve (decompression) may be considered⁷. Surgery carries risks, including poor wound healing, infection and scarring⁶. Before any operation, ask about the likely benefit, the recovery and the risks.

A cortisone (corticosteroid) injection is another option. It carries a risk of tendon tear or rupture, so it's generally a last resort⁸, and more than one injection is generally not recommended². How well injections work once simple care has failed isn't clear yet.

If you have diabetes, the role of surgery is debated⁶, so discuss it carefully with your doctor.

How long does it take to get better, and can it come back?

How long recovery takes, how often it returns and what prevents that aren't clear yet. What is clear is that acting early matters: delay can raise the risk of irreversible nerve damage², and untreated or stubborn tarsal tunnel syndrome can lead to persistent pain, weakness and muscle wasting⁶.

Get symptoms assessed early and follow the plan from your podiatrist, physiotherapist or doctor. It can help to ask how to reduce triggers in your situation, such as how much you walk or run and what footwear you wear. If symptoms persist, spread or come back, let your clinician know so the plan can be reviewed.