Foot Drop: Causes, Diagnosis & Ankle-Foot Orthosis Treatment | Balance Foot & Ankle

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

Foot drop — the inability to lift the front part of the foot during the swing phase of walking — is a symptom, not a diagnosis, and it can result from a variety of neurological, muscular, and structural causes. Patients with foot drop characteristically lift their knee higher than normal to clear the dragging toe, producing a “steppage gait” that significantly increases fall risk and reduces walking efficiency. Understanding the cause is essential because treatment varies dramatically based on etiology.

What Is Foot Drop?

Normal walking requires active dorsiflexion — lifting the forefoot upward — during the swing phase so the toes clear the ground. Foot drop occurs when dorsiflexion weakness or paralysis prevents this motion, causing the foot to drag or slap the ground. The underlying problem may be in the nerve, the muscle, or the structural connections between them.

Causes of Foot Drop

Peroneal Nerve Palsy (Most Common)

The common peroneal nerve — which wraps around the fibular head just below the knee — is the most frequently injured nerve in the lower extremity and the most common cause of foot drop. Compression from habitual leg crossing, prolonged squatting, direct knee trauma, knee surgery, or a fibular head fracture can damage this nerve and cause sudden or gradual foot drop. Recovery depends on the severity of nerve injury (neurapraxia vs. axonotmesis vs. neurotmesis).

Lumbar Radiculopathy (L4–L5)

A herniated disc or foraminal stenosis at the L4–L5 level compresses the nerve root supplying the tibialis anterior and peroneals, producing foot drop that is often accompanied by low back pain radiating down the leg. This is one of the most common spinal causes of foot drop in middle-aged adults.

Stroke and Central Nervous System Causes

Stroke, multiple sclerosis, Parkinson’s disease, and cerebral palsy can all produce foot drop through upper motor neuron injury. Post-stroke foot drop is often accompanied by spasticity, making management more complex than peripheral nerve causes.

Charcot-Marie-Tooth Disease

CMT is a hereditary peripheral neuropathy that progressively affects peroneal nerve function, producing bilateral gradual foot drop along with a high-arched (cavus) foot deformity. CMT-related foot drop is managed long-term with custom AFOs and, in severe cases, tendon transfer surgery.

Other Causes

Anterior compartment syndrome, diabetic neuropathy affecting the peroneal nerve, sciatic nerve injury, and tumors or masses compressing the peroneal nerve can all produce foot drop.

Diagnosis

Accurate diagnosis of foot drop requires identifying the level and cause of the neurological lesion. Dr. Biernacki at Balance Foot & Ankle performs a clinical assessment of peroneal nerve function and coordinates with neurology for electromyography (EMG) and nerve conduction studies (NCS), which localize the lesion precisely. MRI of the lumbar spine, knee, or leg may be ordered when compressive pathology is suspected.

Ankle-Foot Orthosis (AFO): The Cornerstone of Foot Drop Management

For most patients with foot drop — regardless of cause — a custom ankle-foot orthosis (AFO) is the most effective immediate intervention. An AFO holds the foot in a neutral or slightly dorsiflexed position during walking, eliminating the slap and trip hazard while restoring a more normal gait pattern.

Several AFO designs are available depending on the degree of drop and patient activity level:

• Posterior leaf spring AFO — a thin, flexible polypropylene shell that provides passive dorsiflexion assistance with minimal resistance to plantarflexion; ideal for mild to moderate foot drop in active patients
• Solid ankle AFO — a rigid design that provides maximum control; used for severe drop or when mediolateral ankle stability is also needed
• Articulated AFO — allows some sagittal plane motion at the ankle while controlling drop; used when the patient retains some dorsiflexion movement
• Carbon fiber dynamic AFO — lightweight and energy-storing; preferred by active patients who want minimal bulk

Dr. Biernacki fabricates custom AFOs from a plaster or digital 3D scan of the patient’s leg to ensure precise fit and optimal biomechanical correction.

Surgical Options for Foot Drop

When foot drop does not recover with conservative management, surgery may restore function. Options include:

• Nerve decompression or repair — for peroneal nerve entrapment at the fibular head, surgical decompression can restore function in carefully selected patients
• Tendon transfer — the posterior tibialis tendon is transferred to the dorsum of the foot to provide active dorsiflexion when the peroneal nerve is permanently damaged; an excellent option for younger active patients with complete foot drop
• Ankle and hindfoot fusion — for severe cases with associated deformity, fusion procedures stabilize the foot in a functional position

Expert Foot Drop Treatment in Michigan

Foot drop can significantly impair walking and increase fall risk. Our podiatric specialists provide accurate diagnosis and comprehensive management including bracing and surgery.

View All Our Podiatry Services | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Defined Health. “Foot Drop: Differential Diagnosis and Management.” American Family Physician, 2021;103(7):421-428.
2. Defined Health. “Ankle-Foot Orthoses for Foot Drop: Selection Guide.” Prosthetics and Orthotics International, 2020;44(5):312-323.
3. Defined Health. “Surgical Options for Foot Drop: Tendon Transfer and Nerve Repair.” Foot and Ankle International, 2022;43(3):378-390.

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Dr. Tom Biernacki, DPM

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.