Cavus Foot Deformity: Neurological Workup, Coleman Block Test, and Surgical Reconstruction

Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Township, MI. Last updated April 2026.

Cavus foot deformity — pathological high arch with associated hindfoot varus and forefoot plantarflexion — affects approximately 10% of the population in varying degrees and is the structural foundation underlying recurrent lateral ankle sprains, peroneal tendon pathology, stress fractures of the fifth metatarsal and lateral metatarsals, and Charcot-Marie-Tooth related disability. The critical initial step in cavus foot evaluation is neurological investigation — 60–70% of progressive bilateral cavus feet have an underlying hereditary peripheral neuropathy (most commonly CMT1A) that determines the treatment trajectory — followed by the Coleman block test to distinguish forefoot-driven from hindfoot-driven deformity.

Neurological Workup and Coleman Block Test

Neurological evaluation: ALL bilateral progressive cavus feet require neurological evaluation; muscle weakness pattern — intrinsic minus foot (clawing from intrinsic weakness), peroneal weakness (peroneus brevis weakness produces varus hindfoot), anterior compartment weakness (foot drop); sensory examination; deep tendon reflexes (absent Achilles reflex in CMT); EMG/NCS — confirms hereditary motor sensory neuropathy (HMSN) pattern; genetic testing for CMT1A (PMP22 duplication) when clinical suspicion is high; spine MRI to exclude syringomyelia, tethered cord, and intraspinal lesions. Idiopathic vs. neurogenic cavus: idiopathic (40% of cases) — usually unilateral or mildly asymmetric, stable, less severe; neurogenic (CMT, Friedreich’s ataxia) — bilateral, progressive, associated muscle weakness. Coleman block test: the diagnostic cornerstone for surgical planning — the patient stands with the heel and the lateral border of the foot on a 1-inch wooden block (freeing the first metatarsal head from the ground); hindfoot varus that corrects to neutral = forefoot-driven varus (the plantarflexed first ray drives the hindfoot into varus when it must contact the ground) — flexible deformity amenable to soft tissue + first ray procedures. Hindfoot varus that does NOT correct with Coleman block = fixed hindfoot varus — requires calcaneal osteotomy for structural correction.

Surgical Reconstruction Algorithm

Forefoot-driven flexible varus (Coleman block corrects): (1) first metatarsal dorsiflexion osteotomy — elevates the plantarflexed first ray, removing the deforming force; (2) plantar fascia release — releases the fascial contracture pulling the hindfoot into varus; (3) peroneus longus to peroneus brevis transfer — converts the deforming plantarflexion force on the first ray to an everting force on the hindfoot; (4) Achilles lengthening if equinus is present. Fixed hindfoot varus (Coleman block does not correct): calcaneal sliding osteotomy — laterally displaces the calcaneal tuberosity to correct the varus heel; combined with the above soft tissue procedures. Ankle instability: Broström-Gould ATFL repair is almost always required concurrently — cavus foot and chronic lateral ankle instability are an inseparable pair; the instability recurs without structural correction of the cavus foot. CMT-specific reconstruction: staged procedures as weakness progresses; orthoses (AFO) delay surgery; transfer of functioning muscles to replace non-functioning ones as the neuropathy advances. Dr. Biernacki at Balance Foot & Ankle evaluates and surgically reconstructs cavus foot deformity at our Bloomfield Township and Howell offices. Call (810) 206-1402.

📍 Located in Michigan?

Our board-certified podiatrists treat this condition at two convenient locations. Most new patients are seen the same week.

Book Now →
(810) 206-1402

Frequently Asked Questions

When should I see a podiatrist?

See a podiatrist for any foot or ankle pain that persists more than 2 weeks, doesn’t improve with rest, limits your daily activities, or is accompanied by swelling, numbness, or skin changes. People with diabetes or circulation problems should see a podiatrist regularly even without symptoms.

What does a podiatrist treat?

Podiatrists diagnose and treat all conditions of the foot, ankle, and lower leg including plantar fasciitis, bunions, hammertoes, toenail problems, heel pain, nerve pain, diabetic foot care, sports injuries, fractures, and foot deformities — both surgically and non-surgically.

What can I expect at my first podiatry visit?

Your first visit includes a full medical history, physical examination of your feet and gait, and in-office diagnostic imaging if needed (X-rays, ultrasound). We’ll discuss your diagnosis and create a plan tailored to your foot type. Most visits take 30–45 minutes.

Need Treatment at Balance Foot & Ankle?

Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin see patients at our Howell and Bloomfield Township offices.

Book Online or call (810) 206-1402

Most Common Mistake We See

The most common mistake we see is: Waiting too long before seeking care. Fix: any foot pain lasting more than 4 weeks, or any sudden severe symptom, deserves a professional evaluation rather than more rest.

Warning Signs That Need Same-Day Care

In-Office Treatment at Balance Foot & Ankle

If home treatment isn’t providing relief for your foot and ankle conditions, our podiatry team at Balance Foot & Ankle can help with same-week evaluations and advanced in-office care.