Drop Foot: symptoms, causes and treatments

Drop foot causes

Foot drop is not a disease but rather a symptom of an underlying problem with a nerve, muscle, or anatomical structure that results in weakness or paralysis of the leg muscles that lift your foot. This means that foot drop can be temporary or permanent, it can appear at any age and it can involve one or both feet. Sometimes the foot weakness is accompanied by pain or numbness at the shin or the top of the foot and the toes.

Foot drop is caused by weakness or paralysis of the muscles involved in lifting the forefoot. This may be due to one of three reasons:

Nerve damage

The most common cause of foot drop is injury or compression of the nerve that’s responsible for lifting your forefoot. Called the peroneal nerve, it is a branch of your sciatic nerve that originates behind the outer part of your knee. Because of its exposed location, the peroneal nerve can be damaged from a fall, a sports injury, or even inadvertently during childbirth, hip or knee replacement surgery. Another type of nerve injury that can result in foot drop is an injury to the sciatic nerve root where it originates in the spine. Lastly, certain diseases (such as diabetes) can take their toll on nerve cells, affecting their function.

Muscle or nerve disorders

There are a number of neuromuscular diseases that cause progressive muscle weakness that can involve the legs and feet. These include cerebral palsy, muscular dystrophy, polio, and Charcot-Marie-Tooth disease.

Nervous System disorders

Degenerative conditions affecting the brain and spinal cord can also cause foot drop. These include amyotrophic lateral sclerosis (ALS is also known as Lou Gehrig’s disease), multiple sclerosis, and strokes.

How is foot drop diagnosed?

Foot drop is diagnosed through simple observation. Your doctor observes you while you walk to see if you are able to flex your forefoot upward (dorsiflexion) enough to clear your foot during the swing-through phase. Your doctor will also check the muscle strength of your leg and ankle and may test your sensation at the shin and foot.

If your doctor suspects that your foot drop is being caused by compression of the nerve by bone, tumor, or a cyst at your knee or spine, certain tests might be ordered to help identify the location of the problem. These can include:

• X-rays use low-level radiation to visualize bone or soft tissue growths that can be pressing on the nerve
• Ultrasound uses sound waves to create 2-D images of internal structures and can demonstrate soft tissue swelling, cysts or tumors pressing on the nerve
• CT Scan uses hundreds of x-ray images taken from multiple angles to create cross-sectional views of the body, allowing your doctor to see millimeter thick slices of anatomical structures
• Magnetic Resonance Imaging (MRI) uses radio waves in a magnetic field to create detailed images, particularly of soft tissue
• Electromyography (EMG) and nerve conduction studies (NCS) measure the electrical activity of the muscles (EMG) and nerves (NCS) in order to pinpoint the location of the peroneal nerve injury

Foot drop causes and risk factors

Because the primary cause of foot drop is a compression injury to the peroneal nerve, any activities that can compress this nerve can increase your risk of getting foot drop. Such activities include:

• Crossing your legs. If you habitually sit cross-legged, you may be putting pressure on the peroneal nerve of your top (crossed) leg.
• Prolonged kneeling. People who spend a lot of time kneeling and squatting (like carpet installers or gardeners) are at higher risk of foot drop.
• Wearing a lower leg cast. Plaster boot type casts that end just below the knee can put undue pressure on the peroneal nerve and provoke a foot drop.

How is foot drop treated?

The treatment for foot drop depends on its cause. That is why it’s important to treat the cause of the foot drop as soon as it’s detected, to improve your chances of recovery.

Foot drop treatment options can include:

Drop foot brace

Your doctor may order a custom-fitted brace that puts your foot at 90 degrees to your leg, thus allowing your foot to clear during the swing phase of walking. At UFAI, We make a wonderful brace called Dorsi-Assist that helps pull the toes and ankle up so people don’t trip. This is better than the standard brace for activity. 

Foot drop orthotics

These devices fit inside your shoe and help keep your foot in a normal position.

Physical therapy

Therapy may be ordered to teach you exercises that help strengthen your muscles, reduce joint stiffness, and increase range of motion at the knee and ankle.

Nerve stimulation for drop foot

Your doctor might fit you with a device that uses electricity to stimulate the weak nerve and improve its function while you’re walking.

Foot drop surgery 

Surgery might be considered at different times, such as repairing or freeing up a trapped segment (decompression) of the peroneal nerve in a new-onset foot drop or, if the foot drop has failed to respond to conservative treatment, performing a tendon transfer or bone fusion in order to permanently position the foot at 90 degrees to the lower leg to facilitate walking.

At UFAI, we also do tendon transfers that can help with dorsiflexion of the foot and ankle. 

Choose University Foot and Ankle Institute for drop foot treatment

Our nationally recognized foot and ankle specialists have decades of combined experience and work hard to get you back on your feet and back to your life with the least invasive treatment possible.

With the highest success rates in the country, we have been at the forefront of both conservative as well as surgical options for the treatment of drop foot.