Tarsal Tunnel Syndrome

Lower Limb

Overview

Tarsal tunnel syndrome is a compression neuropathy of the posterior tibial nerve as it passes through the tarsal tunnel behind the medial malleolus. It presents with pain, paresthesia, and numbness in the medial ankle, sole of the foot, and heel, often worsening with activity and relieved by rest. The condition can significantly impact gait and functional mobility if untreated.

Pathophysiology

The posterior tibial nerve becomes compressed within the tarsal tunnel, a fibro-osseous canal formed by the flexor retinaculum, medial malleolus, and talus. Compression may result from space-occupying lesions (ganglions, tenosynovitis, accessory muscles), ankle edema, trauma, excessive pronation, or inflammation of surrounding structures. Chronic compression impairs nerve conduction velocity, leading to demyelination, ischemia, and progressive neurological symptoms including sensory loss and motor dysfunction of intrinsic foot muscles.

Typical Presentation

Site

Medial ankle (behind medial malleolus), heel, sole of foot, medial arch, and plantar surface; symptoms may radiate proximally along medial leg or distally into toes

Quality

Burning, tingling, numbness, or electric shock-like sensations; may include cramping or aching in the foot and heel

Intensity

Mild to severe, typically 4-8/10, often progressive; may be constant or intermittent

Aggravating

Prolonged standing or walking, activities involving ankle inversion/eversion, tight footwear, ankle edema, jumping or running, activities that increase tarsal tunnel pressure

Relieving

Rest and elevation, ankle support or orthotic devices, ice application, removing tight footwear, non-weight-bearing positions

Associated

Ankle swelling, decreased ankle mobility, foot cramps, muscle weakness in foot intrinsics, toe clawing, altered gait, cold feet, difficulty with fine foot movements

Orthopaedic Tests

Tinel's Sign (Tarsal Tunnel)

Procedure

Percuss or tap directly over the posterior tibial nerve as it passes posterior and inferior to the medial malleolus. Perform the test with the foot relaxed and in slight plantarflexion.

Positive Finding

Reproduction of tingling, numbness, or electric shock sensation in the plantar aspect of the foot and toes (distal to the percussion site)

Sensitivity / Specificity

42–100% / null

Interpretation

A positive Tinel's sign suggests nerve irritation or compression at the tarsal tunnel; however, it lacks specificity and may occur with other neuropathies. Used as a screening test, not confirmatory.

Dorsiflexion–Eversion Test

Procedure

Position the patient supine or seated. Passively dorsiflex and evert the foot while palpating the tarsal tunnel region posterior to the medial malleolus. Maintain the stretch for 5–10 seconds.

Positive Finding

Reproduction of symptoms (pain, tingling, or numbness) in the medial plantar, lateral plantar, or calcaneal nerve distribution

Sensitivity / Specificity

null / null

Interpretation

Stretching and compressing the posterior tibial nerve via dorsiflexion-eversion may provoke symptoms if the nerve is entrapped; suggests mechanical compression.

Tarsal Tunnel Compression Test (Manual Compression)

Procedure

Apply sustained direct pressure over the posterior tibial nerve at the tarsal tunnel (posterior to medial malleolus) for 30–60 seconds while the patient is seated or supine. Observe for symptom reproduction.

Positive Finding

Reproduction of paresthesias, numbness, or pain in the foot distribution of the posterior tibial nerve (medial plantar and/or lateral plantar nerve territories)

Sensitivity / Specificity

null / null

Interpretation

Direct compression over the tarsal tunnel may reproduce symptoms if nerve entrapment is present. Absence of symptoms does not exclude the diagnosis.

Heel Walking (Clinical Observation)

Procedure

Ask the patient to walk on their heels for 30–60 seconds, observing for difficulty lifting the forefoot or reproducing medial plantar pain/paresthesias.

Positive Finding

Inability or difficulty performing the movement, or reproduction of symptoms in the medial plantar region

Sensitivity / Specificity

null / null

Interpretation

Heel walking stresses the posterior tibial nerve and may provoke symptoms; useful as a functional screening test to support clinical suspicion.

Nerve Conduction Studies (NCS) and Electromyography (EMG)

Procedure

Formal electrodiagnostic testing performed by a trained technician. Measures conduction velocity and latency of the posterior tibial nerve and assesses for denervation in intrinsic foot muscles.

Positive Finding

Prolonged distal motor latency (typically >6.5 ms), reduced compound motor action potential amplitude, or signs of denervation in foot muscles supplied by the posterior tibial nerve

Sensitivity / Specificity

40–80% / 85–95%

Mondelli et al., 2005, Electroencephalography and Clinical Neurophysiology

Interpretation

Gold standard electrodiagnostic test for tarsal tunnel syndrome. High specificity supports diagnosis; negative findings do not exclude early or mild compression.

Magnetic Resonance Imaging (MRI) of the Ankle and Foot

Procedure

High-resolution MRI (1.5–3 T) with axial and coronal T2-weighted sequences focused on the medial ankle and tarsal tunnel region. Assess for nerve enlargement, masses, fibrosis, or anatomical variants.

Positive Finding

Posterior tibial nerve enlargement (>8 mm²), ganglion cyst, tenosynovitis, space-occupying lesion, or accessory muscle (e.g., abductor hallucis accessorius) causing compression

Sensitivity / Specificity

null / null

Interpretation

Identifies structural causes of compression (cysts, tumours, anatomical variants). Helpful for confirming suspected diagnosis and guiding treatment planning; does not assess functional nerve impairment.

⚠ Red Flags

  • •Acute severe pain with evidence of compartment syndrome (pain out of proportion, pain with passive stretch)
  • •Progressive neurological deficit with motor weakness and sensory loss
  • •Signs of complex regional pain syndrome
  • •Unexplained systemic symptoms suggesting underlying metabolic or rheumatological disease
  • •History of trauma with acute onset and signs of fracture
  • •Suspected space-occupying lesion (palpable mass, progressive unilateral symptoms)

⚡ Yellow Flags

  • •High anxiety or catastrophizing about symptoms
  • •Excessive health beliefs linking minor symptoms to serious disease
  • •Significant functional limitation disproportionate to clinical findings
  • •History of chronic pain conditions or fibromyalgia
  • •Pending litigation or compensation claims related to foot pain
  • •Reluctance to engage in rehabilitation or activity modification
  • •High perceived disability with low pain levels

Osteopathic Techniques

Region

Medial ankle and tarsal tunnel

Technique

Soft Tissue

Rationale

Gentle soft tissue mobilization to the flexor retinaculum, plantar fascia, and surrounding muscles reduces local inflammation and improves tissue extensibility, potentially relieving nerve compression and improving local circulation

Region

Ankle joint (talocrural and subtalar)

Technique

Articulation

Rationale

Gentle ankle mobilizations improve joint mechanics, reduce abnormal pronation patterns, and decrease mechanical stress on the tarsal tunnel, enhancing nerve gliding and reducing compression

Region

Plantar foot and intrinsic muscles

Technique

Soft Tissue

Rationale

Release of hypertonic plantar fascia and intrinsic foot muscles reduces tension on the posterior tibial nerve and improves circulation to facilitate nerve recovery

Region

Posterior compartment (calf and posterior leg)

Technique

MET

Rationale

Muscle energy techniques to the plantaris, soleus, and gastrocnemius muscles reduce compartment tension, improve venous drainage, and decrease indirect compression on the tarsal tunnel

Region

Subtalar joint and midfoot

Technique

Functional

Rationale

Functional release techniques address abnormal foot mechanics and excessive pronation, normalizing structural relationships and reducing aberrant forces compressing the tarsal tunnel

Region

Lumbar spine and sciatic nerve

Technique

Articulation

Rationale

Treatment of spinal restrictions and sciatic nerve tension reduces referred symptoms and normalizes proximal neural tension, which may contribute to tarsal tunnel dysfunction through altered nerve physiology

Add-On Approaches

Chinese Medicine

Acupuncture targeting acupoints KI3 (Taixi), KI1 (Yongquan), and LIV3 (Taichong) may improve circulation and reduce nerve irritation; moxibustion for deficiency patterns; herbal remedies addressing qi stagnation and blood stasis

Chiropractic

Foot and ankle manipulations to improve subtalar and talocrural joint mechanics; correction of pronation patterns through foot orthotics; soft tissue therapy to address compartment restrictions

Physiotherapy

Progressive strengthening of foot intrinsics and tibialis posterior; proprioceptive training and balance exercises; gait re-education to normalize ankle mechanics and reduce excessive pronation; progressive walking programs

Remedial Massage

Deep tissue massage to release plantaris, soleus, and flexor digitorum longus muscles; myofascial release of the plantar fascia; trigger point therapy to reduce referred symptoms; lymphatic drainage to manage edema

Rehabilitation Exercises

Ankle Alphabet

Range of MotionBeginner

Plantar Fascia Stretch with Towel Roll

StretchingBeginner

Calf Stretch (Soleus Emphasis)

StretchingBeginner

Short Foot Exercise (Intrinsic Foot Muscles)

StrengtheningBeginner

Tibialis Posterior Isometric Hold

StrengtheningBeginner

Toe Curls with Resistance Band

StrengtheningIntermediate

Single-Leg Stance on Firm Surface

BalanceIntermediate

Foot Inversion and Eversion Control Exercise

PosturalIntermediate

Seated Marbles Pickup with Toes

StrengtheningBeginner

Toe Flexion and Extension Sequence

Range of MotionBeginner

Tandem Walking (Heel-Toe)

BalanceIntermediate

Supported Pool Walking or Swimming

CardiovascularBeginner

Referral Criteria

  • •Severe progressive neurological deficit with motor weakness or significant sensory loss not responding to conservative management after 6-8 weeks
  • •Imaging evidence of significant space-occupying lesion (ganglion, tumor, tenosynovitis) causing compression
  • •Failure to improve with appropriate conservative osteopathic and physiotherapy management after 8-12 weeks
  • •Suspected complex regional pain syndrome or neuropathic pain syndrome requiring specialist pain management
  • •Electrophysiological confirmation of significant nerve conduction abnormality warranting consideration of surgical decompression
  • •Systemic symptoms or metabolic factors (diabetes, thyroid dysfunction, rheumatological disease) requiring medical management
  • •Acute severe presentation with evidence of trauma or fracture requiring imaging and orthopedic assessment
  • •Ankle instability or significant structural damage identified during assessment requiring imaging or specialist review