Tarsal Tunnel Syndrome


  • The tarsal tunnel is a narrow space posterior to the medial malleolus. The tunnel is covered with the flexor retinaculum that protects and maintains the structures contained within.
  • Tarsal tunnel syndrome is a compression or squeezing on the posterior tibial nerve that produces symptoms anywhere along the path of the nerve.
  1. A person with flat/pronated feet is at risk for developing tarsal tunnel syndrome because the outward tilting of the heel that occurs with “fallen” arches can produce strain and compression on the nerve.
  2. An enlarged or abnormal structure that occupies space within the tunnel can compress the nerve. Some examples include a varicose vein, ganglion cyst, swollen tendon, and arthritic bone spur.
  3. An injury, such as an ankle sprain, may produce inflammation and swelling in or near the tunnel, resulting in compression of the nerve.
  4. Systemic diseases such as arthritis can cause swelling, thus compressing the nerve.

Diagnostic tips

  1. Tingling, burning, or a sensation similar to an electrical shock inside of the ankle and/or on the bottom of the foot.
  2. Numbness inside of the ankle and/or on the bottom of the foot.
  3. Pain (including shooting pain) inside of the ankle and/or on the bottom of the foot.
  4. Symptoms may extend to the heel, arch, toes, and even the calf.
  5. Aggravated by overuse of the foot, such as in prolonged standing, walking, exercising, or beginning a new exercise program.

Tests and Imaging

  1. It is important to rule out L4-S3 spinal nerve compression.
  2. Direct pressure or tapping on the nerve reproduces patient’s symptoms (Tinel’s sign)
  3. Weightbearing x-rays and ultrasound of the foot should be assessed to review for any obvious pathology in the hind foot.
  4. A CT scan or MRI is sometimes indicated to rule out a mass, which may be irritating the nerve.

Immediate Treatment

  1. Advise weight loss to decrease the repetitive forces through this area of the foot.
  2. Advise activity modification to limit the amount of standing and walking and thereby the amount of repetitive injury to this area.
  3. Corticosteroid injections may help to decrease the swelling around the nerve in the short and intermediate term.

Possible Referral

  1. Podiatry for footwear advice, orthoses, strapping.
  2. Orthopaedic foot surgeon for possible release of flexor retinaculum.