Tarsal tunnel syndrome occurs when the tibial nerve is compressed as it passes through the tarsal tunnel — a narrow fibrous channel behind the medial malleolus (the inner ankle bone). The symptoms are distinctive: burning, tingling, or numbness along the sole of the foot and toes, often worse with prolonged standing or walking, sometimes present at rest. It's frequently misdiagnosed as plantar fasciitis because the symptom location overlaps. They're different problems with different mechanisms.
What drives tibial nerve compression
The tarsal tunnel has fixed walls — bone on one side, the flexor retinaculum on the other. Anything that reduces the space inside that tunnel compresses the nerve. The usual culprits:
Pronation and valgus foot mechanics. When the foot pronates excessively, the tarsal tunnel narrows. This is the most common structural driver, and it originates in the ankle and subtalar joint mechanics — not just the foot position itself.
Posterior tibial tendon dysfunction. The posterior tibial tendon runs directly through the tarsal tunnel alongside the nerve. When it's thickened or inflamed from overload, it reduces available space and directly compresses the nerve.
Ankle swelling and fibrosis. Post-sprain fibrosis in the tarsal tunnel region reduces the tunnel volume permanently unless addressed with manual therapy. Many patients with a history of ankle sprains who develop tarsal tunnel symptoms have this component.
The tibial nerve originates in the lumbar spine. When symptoms are severe or not fully resolving with local treatment, the lumbar mechanics are assessed. A double-crush phenomenon — compression at two levels along the same nerve — is more common in tarsal tunnel than most providers check for.
What actually works
Active Release Techniques® for the flexor retinaculum, posterior tibial tendon, and calf musculature — releasing the adhesions and fibrosis restricting the tunnel. Chiropractic adjustment of the talocrural and subtalar joints to restore mechanics that reduce tunnel narrowing. Addressing the pronation pattern with either movement retraining or, where indicated, custom orthotics.
For chronic tarsal tunnel with significant fibrosis, Shockwave Therapy (ESWT) to the tunnel region breaks down the scar tissue compressing the nerve from outside the tunnel walls. This is particularly useful in presentations that have been present for more than six months without resolution.
Lumbar assessment is included when the clinical picture warrants it — particularly when the nerve symptoms extend above the ankle or when the foot presentation doesn't fully respond to local treatment alone.