Quick answer
Drop foot is the inability to lift the front of the foot off the ground. It’s a symptom rather than a diagnosis — the actual problem is somewhere along the nerve and muscle pathway that lifts the foot. Common upstream causes include peripheral neuropathy affecting the motor nerves, lumbar nerve-root compression in the back, peroneal nerve compression at the knee, stroke, and inherited disorders like Charcot-Marie-Tooth disease. Finding the source matters because treatment varies dramatically based on cause.
How to recognize it
The signs are usually noticeable to others before the affected person fully accepts them:
- Dragging the foot when walking, especially the toes
- High-stepping gait — lifting the knee higher than usual to compensate
- Slapping foot sound when the foot hits the ground
- Tripping on rugs, curbs, uneven ground
- Difficulty climbing stairs with the affected leg
- Weakness when trying to pull the toes up toward the shin
- Numbness on the top of the foot or outside of the lower leg (depending on cause)
What’s actually happening
Lifting the foot involves:
- Brain motor cortex sends signal
- Spinal cord transmits down
- L4-L5 nerve roots branch off
- Sciatic nerve in the back
- Peroneal (fibular) nerve at the side of the knee
- Tibialis anterior and other muscles do the lifting
A break anywhere along this pathway can cause foot drop.
The most common causes
Peroneal nerve injury at the knee
The most common single cause. The peroneal nerve runs around the outside of the knee and is vulnerable to:
- Crossing legs for prolonged periods
- Squatting or kneeling for hours
- Pressure from casts, braces, or tight wraps
- Direct trauma — knee fractures, dislocations, injections
- Surgical positioning during long operations
- Weight loss with thin legs
Often improves over weeks to months once the source of pressure is removed.
L5 lumbar disc herniation
A pinched L5 nerve root in the lower back can cause foot drop along with back pain and sometimes leg pain (sciatica). Common in working-age adults.
Stroke
Sudden foot drop on one side, especially with arm weakness or other neurological symptoms, can be a stroke.
Multiple sclerosis
Demyelinating disease can affect the motor pathway anywhere.
Charcot-Marie-Tooth and other neuropathies
Inherited or acquired neuropathies often cause bilateral, gradually progressive foot drop.
Other causes
- ALS and other motor neuron diseases (rare but serious)
- Spinal tumors
- Diabetic neuropathy (advanced)
- Poliomyelitis (rare in vaccinated populations)
- Compartment syndrome (acute, surgical emergency)
Diagnosis
The workup depends on the suspected cause but typically includes:
- History and physical exam — onset pattern, associated symptoms, exam of strength and sensation
- Reflex testing
- Sensation testing — patterns help localize the lesion
- Imaging — MRI of the lumbar spine for suspected disc disease, MRI of the knee for peroneal nerve issues
- Electromyography (EMG) and nerve conduction studies — confirm and localize the nerve injury
- Sometimes additional: blood tests for systemic causes, brain imaging for stroke
Treatment
The most important treatment is addressing the underlying cause:
- Peroneal compression — remove the source, expect spontaneous recovery over weeks to months
- L5 disc herniation — physical therapy, sometimes epidural steroid injections, sometimes surgery
- Stroke — acute stroke care, rehabilitation
- Inherited neuropathies — supportive care, bracing
- Tumors, ALS, etc. — specific treatments for those conditions
Symptomatic management
Until or unless the foot drop resolves:
- Ankle-foot orthosis (AFO) — a brace that holds the foot in a neutral position, dramatically improves walking and reduces tripping
- Functional electrical stimulation — devices that electrically activate the foot-lifting muscles during walking
- Physical therapy — strengthening, gait training, balance
- Tendon transfer surgery — for permanent foot drop, transfers a working tendon to do the job of the lost one
Bottom line
Foot drop isn’t really a foot problem — it’s a problem with the system that controls the foot. The cause matters more than the symptom. Many cases improve on their own once the underlying cause is identified and addressed. Even when permanent, modern bracing and physical therapy let most people walk well and stay active.
Last updated: April 25, 2026
About the author
Written and reviewed by a Doctor of Podiatric Medicine (DPM) practicing in Arizona for 6+ years. Board-certified by the American Board of Podiatric Medicine (ABPM); graduate of Midwestern University Arizona College of Podiatric Medicine.
Last clinically reviewed: April 25, 2026