Drop Foot: symptoms, causes and treatments

What causes drop foot? 

Drop foot can have various causes. It’s actually a symptom of an underlying problem with a nerve, muscle, or anatomical structure resulting in weakness or paralysis of the leg muscles that lift your foot. This means that while foot drop can sometimes be permanent, it may also only be temporary. 

Depending on the cause, drop foot 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. This can signal peripheral neuropathy, in which the nerve signals traveling between your brain and extremities are disrupted.

In general, foot drop caused by weakness or paralysis of the muscles involved in lifting the forefoot can 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 common peroneal nerve or fibular nerve, it is a branch of your sciatic nerve that originates behind the outer part of your knee and runs down your fibula and tibia (shin and calf bones). 

Because of this peripheral nerve’s exposed location, it can be easily damaged by events such as: 

• • A fall
  • A sports injury
  • 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 the nerve 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 sudden or progressive muscle weakness involving the legs and feet. Some nerve disorder causes include 

• • Cerebral palsy
  • Muscular dystrophy
  • Polio
  • Spinal muscular atrophy
  • Charcot-Marie-Tooth disease

Nervous system disorders 

Degenerative conditions affecting the brain and spinal cord can also cause foot drop. Neurological disorders that may cause drop foot include amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease) and multiple sclerosis. Drop foot after a stroke is not uncommon. 

What are the symptoms of drop foot? 

The primary symptom of drop foot is dragging the forefoot when walking. However, this may lead to secondary symptoms such as a change in gait. For example, to compensate, a person with foot drop might lift their thigh higher (called steppage gait) or swing their leg around (called circumduction) to help their drop foot clear the floor. Sometimes, you’ll notice their weak foot slapping the floor when they walk.

How is foot drop diagnosed?

The podiatrists at University Foot & Ankle Institute can typically diagnose drop foot with simple observation, a physical exam, and imaging tests. To start, our doctor will observe you while walking to see if you are able to flex your forefoot upward (dorsiflexion) enough to clear your foot during the swing-through phase. We’ll also check the muscle strength of your leg and ankle and may test your sensation at the shin and foot.

If our doctor suspects that your foot drop is being caused by a bone, tumor, or cyst compressing the nerve, we can order other tests to identify the location of the problem. 

These can include:

• X-rays to visualize bone or soft tissue growths that might be pressing on the nerve
• Ultrasound to create 2-D images of internal structures and view any soft tissue swelling, cysts, or tumors pressing on the nerve.
• CT scans to create cross-sectional views of the body, allowing us to see millimeter-thick slices of anatomical structures.
• Magnetic Resonance Imaging (MRI) to create detailed images of soft tissue.
• Electromyography (EMG) and nerve conduction studies (NCS) that measure the electrical activity of the muscles and nerves to pinpoint the location of a peroneal nerve injury.

What are foot drop causes and risk factors? 

Because the primary cause of foot drop is a compression injury to the peroneal nerve, any activities that 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 the cause. That is why it’s important to consult a foot expert to determine and treat the underlying cause. Beginning treatment as quickly as possible improves your chances of recovery.

Foot drop treatment options can include:

Drop foot brace 

We can order a custom-fitted brace that holds your foot at a 90-degree angle to your leg, thus allowing your foot to move safely unhindered during the swing phase of walking. 

These are referred to as ankle-foot orthoses (AFO). At UFAI, we make an advanced orthopedic drop foot leg brace called Dorsi-Assist that helps pull the toes and ankle to reduce the risk of tripping and help the front part of the foot clear the floor. This is better than standard splints.

Foot drop orthotics 

These shoe inserts can effortlessly slip into your favorite shoes and help keep your foot in a normal position.

Physical therapy 

Therapy for foot drop can teach you exercises to help strengthen your muscles, reduce joint stiffness, and increase your range of motion at the knee and ankle.

Nerve stimulation for drop foot 

For some types of drop foot, our doctor might fit you with a device that uses electrical stimulation on the weak nerve to improve its function while you’re walking.

Surgery for drop foot 

In more complicated cases, we may turn to surgery to relieve your drop foot. Decompression surgery can repair or free up a trapped segment of the peroneal nerve. 

If your foot drop does not respond to conservative treatment, we may perform a tendon transfer or bone fusion in order to permanently position the foot at a 90 degree angle 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 & 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.

While we always opt for the most conservative treatment, you can be assured that you are being truly cared for by University Foot and Ankle Institute you have decades of experience and state-of-the-art techniques in your corner.

To schedule a consultation, please call (855) 872-5249 or make an appointment now.

University Foot and Ankle Institute is conveniently located throughout Southern California and the Los Angeles area. Our foot doctors are available at locations in or near Santa Monica, Beverly Hills, West Los Angeles, El Segundo, Northridge, Downtown Los Angeles, Westlake Village, Santa Barbara, and Valencia.