Foot Drop: Causes, Treatment and Recovery

What foot drop looks like

Foot drop changes the way you walk. You may notice:

• Toe drag: the toes catch on carpets, curbs or stairs, causing trips
• Foot slap: the foot smacks down after the heel strikes, because it cannot be lowered smoothly
• Steppage gait: lifting the knee higher than normal, as if climbing stairs, to clear the foot
• Hip hiking or circumduction: swinging the leg out to the side
• Numbness on the top of the foot or outer shin, depending on the cause

Foot drop can be mild, noticed only when tired, or complete, with no ability to lift the foot at all. It may affect one or both feet. For a broader look at weakness of the toes and foot, including pushing down and toe curling, see foot or toe weakness.

Why foot drop happens

The muscles at the front of the shin, mainly the tibialis anterior, lift the foot. They are powered by the deep peroneal nerve, a branch of the common peroneal (fibular) nerve, which comes from the sciatic nerve and ultimately from the L4, L5 and S1 nerve roots in the lower spine. Damage anywhere along this path, or in the brain and spinal cord that control it, can cause foot drop.

Foot drop causes

Peroneal nerve compression

This is the most common cause. The common peroneal nerve wraps around the head of the fibula just below the outside of the knee, where it lies under the skin. It can be compressed or injured by:

• habitually crossing the legs
• prolonged squatting or kneeling, for example in gardening or flooring work
• a tight cast, brace or compression stocking
• long periods lying still during surgery, illness or in bed
• significant weight loss, which removes fat padding around the nerve
• knee injuries, dislocations and fractures of the fibula
• knee or hip surgery

Peroneal foot drop typically comes with numbness on the top of the foot and the outer shin, but no back pain, and the ability to turn the foot inward is normal.

L5 nerve root compression

A herniated disc or spinal stenosis pressing on the L5 root causes lumbar radiculopathy: back pain with pain and tingling down the outer leg into the top of the foot. Unlike peroneal nerve palsy, turning the foot inward and moving the hip outward can also be weak.

Nerve disease

Peripheral neuropathy from diabetes, alcohol or vitamin deficiency can cause foot drop in both feet. Charcot-Marie-Tooth disease, an inherited neuropathy, causes slowly progressive foot drop with high arches and thin calves.

Brain and spinal cord causes

Stroke, multiple sclerosis, brain injury, cerebral palsy and spinal cord injury can cause foot drop, often with a stiff leg and brisk reflexes.

Muscle and motor neuron disease

ALS may begin with painless foot drop in one leg. Some muscular dystrophies weaken the shin muscles.

How foot drop is diagnosed

1. Examination: strength of each foot and ankle movement, reflexes, sensation, and inspection of the knee, back and spine. Testing foot inversion and hip abduction helps separate an L5 root problem from a peroneal nerve problem.
2. Nerve conduction studies and EMG: these locate the damage, show how severe it is, and help predict recovery. They are most informative about 3 weeks after onset.
3. MRI of the lumbar spine: if a disc or stenosis is suspected.
4. Ultrasound or MRI of the knee: to look for a cyst or mass pressing on the peroneal nerve.
5. Blood tests: glucose, HbA1c, B12 and other tests for neuropathy.
6. Brain or spinal cord MRI if there are signs of a central cause.

Foot drop treatment

Treat the cause

• Stop crossing your legs and avoid prolonged squatting or kneeling.
• Loosen or pad tight casts and braces.
• Disc-related foot drop: decompression surgery may be offered, particularly when weakness is severe or worsening. Earlier surgery may give a better chance of recovery.
• Release surgery for a trapped peroneal nerve that does not recover, or removal of a cyst pressing on it.
• Control blood sugar and correct vitamin deficiencies in neuropathy.

Ankle-foot orthosis (AFO)

An AFO is a lightweight brace, usually plastic or carbon fiber, worn inside the shoe. It holds the foot up while walking, preventing toe drag and falls. Off-the-shelf versions suit mild cases, and custom AFOs fit better for long-term use. Functional electrical stimulation (FES) devices, which stimulate the peroneal nerve with each step, are an alternative for some people with stroke or multiple sclerosis.

Physical therapy

A physical therapist works on strength, range of motion and walking pattern. Common foot drop exercises include:

• Ankle dorsiflexion with a resistance band: loop a band around the top of the foot and pull the toes toward you
• Toe raises: sitting with feet flat, lift the front of the feet while keeping heels down
• Calf stretch: to prevent a tight Achilles tendon, which makes foot drop worse
• Towel scrunches and marble pickups for small foot muscles
• Balance training on one leg, with support nearby

Electrical muscle stimulation may help keep weak muscles active while the nerve recovers.

Surgery for permanent foot drop

If foot drop persists after 12 to 18 months, a tendon transfer (often moving the posterior tibial tendon to the top of the foot) can restore active lift. Ankle fusion is an option in some cases.

Foot drop recovery time

Recovery depends on the cause and severity:

Nerves regrow at roughly 1 mm a day (about 1 inch a month), which explains why recovery after nerve injury takes months.

Living with foot drop

• Wear shoes with firm soles and good grip, and avoid slippers and flip-flops.
• Clear walkways of rugs and cables, and use night lights.
• Check numb feet daily for blisters or pressure from the brace.
• Use a cane on uneven ground if balance is affected.

Frequently asked questions

What is the most common cause of foot drop?

The most common cause is compression of the common peroneal nerve just below the knee, often from leg crossing, prolonged squatting, a tight cast or weight loss. A pinched L5 nerve root from a herniated disc in the lower back is the next most common cause.

Can foot drop be cured?

It often improves or resolves when the cause is treated early, such as removing pressure on the peroneal nerve or relieving a herniated disc. Foot drop from progressive nerve or muscle disease is usually permanent, but braces and therapy keep people walking safely.

How long does foot drop take to heal?

Mild nerve compression can recover within weeks to 3 months. More severe nerve injuries take 6 to 12 months or longer, because nerves regrow slowly. Recovery is less likely if complete weakness has lasted many months.

What exercises help foot drop?

Useful exercises include ankle dorsiflexion against a resistance band, toe raises while seated, calf stretches, towel scrunches and balance training. A physical therapist can tailor a program and check your walking pattern.

Is foot drop a sign of a stroke?

It can be, especially if it starts suddenly with weakness in the arm or face, slurred speech or confusion. In that case, call 911 or your local emergency number. Most foot drop, however, comes from nerve compression in the leg or back.