Tarsal Tunnel Syndrome: The Foot Condition That Mimics Neuropathy

You know the feeling when your hand goes numb because you slept on your arm wrong? Now imagine that sensation — burning, tingling, electric pins-and-needles — happening in the bottom of your foot, repeatedly, without an obvious cause. That's what tarsal tunnel syndrome feels like, and it's far more common than most people realize.

Tarsal tunnel syndrome is a compressive neuropathy of the posterior tibial nerve as it passes through the tarsal tunnel — a narrow fibro-osseous channel behind and below the medial malleolus (the bony bump on the inside of your ankle). Think of it as carpal tunnel syndrome's lesser-known cousin, affecting the foot instead of the hand.

Anatomy of the Problem

The tarsal tunnel is formed by the bones of the ankle on one side and the flexor retinaculum (a band of fibrous tissue) on the other. Through this tight space passes the posterior tibial nerve along with the posterior tibial artery, veins, and three tendons. There's not much room to spare, and anything that increases pressure within this space can compress the nerve.

As the posterior tibial nerve passes through the tunnel, it typically divides into three branches: the medial plantar nerve, the lateral plantar nerve, and the medial calcaneal nerve. These branches supply sensation to the bottom of the foot, the heel, and the toes. Compression can affect any or all of these branches, which is why symptoms can vary in location and pattern.

What Causes Compression

Flat feet and overpronation are the most common contributing factors. When the arch collapses, the structures on the medial side of the ankle are placed under tension and the tarsal tunnel narrows. This is why tarsal tunnel syndrome often coexists with posterior tibial tendon dysfunction.

Space-occupying lesions within or adjacent to the tunnel — ganglion cysts, lipomas, varicose veins, accessory muscles, or an os trigonum (an extra bone) — physically compress the nerve. These are found in roughly 20–30% of tarsal tunnel cases.

Other contributing factors include ankle sprains or fractures (scar tissue or swelling narrows the tunnel), systemic conditions that cause nerve inflammation (diabetes, hypothyroidism, rheumatoid arthritis), and prolonged standing or repetitive dorsiflexion-eversion activities.

Symptoms to Recognize

The hallmark symptoms are burning, tingling, numbness, or shooting pain along the bottom of the foot, the heel, or the toes. Unlike plantar fasciitis — which produces sharp, localized pain — tarsal tunnel symptoms tend to be diffuse, radiating, and neurological in character.

Symptoms often worsen with prolonged standing, walking, or specific ankle positions. Many patients report that symptoms are worse at night, disturbing sleep. Some describe a sensation of walking on a bunched-up sock or a hot spot on the sole. The symptoms may extend along the inside of the ankle as well.

One distinguishing feature: Tinel's sign — tapping over the tarsal tunnel on the inside of the ankle reproduces or worsens the tingling symptoms radiating into the foot. This is a useful clinical test.

The Diagnostic Challenge

Tarsal tunnel syndrome is frequently misdiagnosed or overlooked. Its symptoms overlap with peripheral neuropathy (especially diabetic neuropathy), plantar fasciitis, and lumbar radiculopathy (nerve compression in the lower back). Patients often go through multiple evaluations before the correct diagnosis is made.

A thorough clinical exam — including Tinel's sign, nerve provocation tests, biomechanical assessment, and evaluation for flat feet — is the starting point. Advanced imaging (MRI) can identify space-occupying lesions within the tunnel. Nerve conduction studies and electromyography (EMG) can confirm nerve damage and localize the compression, though these tests have limitations and can produce false negatives in early disease.

Treatment Options

Conservative treatment is effective for many patients, especially when started early. Custom orthotics that support the medial arch reduce the pronation that narrows the tarsal tunnel — this is often the single most impactful intervention. Anti-inflammatory measures (oral NSAIDs, icing over the tarsal tunnel) reduce local swelling. Activity modification reduces repetitive nerve irritation. Physical therapy focused on nerve gliding exercises and calf flexibility can improve symptoms. And laser therapy may help reduce nerve inflammation and pain.

Corticosteroid injection into the tarsal tunnel can provide temporary relief and serves as both a therapeutic and diagnostic tool — if injection significantly reduces symptoms, it supports the diagnosis.

Surgical decompression (tarsal tunnel release) is considered when conservative treatment fails after several months, or when imaging reveals a space-occupying lesion that won't resolve on its own. The procedure releases the flexor retinaculum to create more room for the nerve, and any identified mass is removed. Outcomes are generally good when a clear compressive cause is identified.

The Importance of Early Treatment

Nerve compression is time-sensitive. The longer a nerve remains compressed, the more likely it is to sustain permanent damage. Patients treated early in the course of tarsal tunnel syndrome respond much better to conservative care than those who have endured symptoms for months or years. If you're experiencing burning, tingling, or numbness in the bottom of your foot — especially if it's accompanied by flat feet — don't assume it's just "bad circulation." An evaluation can identify whether nerve compression is the cause and prevent progression to irreversible nerve injury.