What Is Foot Drop?

If your doctor has diagnosed you with drop foot, you don’t need anyone to tell you how very frustrating this condition can be. Drop foot and foot drop are interchangeable terms that describe an abnormal neuromuscular (nerve and muscle) disorder that affects the ability to flex your foot at the ankle. Drop foot is further characterized by an inability to point your toes skyward (known as dorsiflexion) or rotate your foot inward or outward.

In short, drop foot mean your foot won’t cooperate with just about anything you try to do in daily life—whether that’s walking, climbing stairs, or driving. Pain, weakness, and numbness are also sometimes an issue, and can leave you frustrated about what’s happening to your body.

Let’s take a closer look at what exactly drop foot is, how it occurs, and what you can do about it.

Your Peroneal Nerve and Drop Foot

Science lesson: The body’s nerves are classified as either central (brain and spinal cord) or peripheral (the rest of the body, including the arms and legs). Nerves control the strength and movement of muscles, along with sensations, including pain, hot, cold, vibration, and pressure. Nerve damage can also affect the muscles that the nerve controls, along with sensation in that area.

Drop foot is also a symptom of underlying nerve problem. It can be caused by injury to the L4 and L5 lumbar nerves in the lower back or the peroneal nerve, located behind the knee. “The L4 nerve and L5 nerve are responsible for what we call dorsiflexing your ankle, meaning bringing your ankle up,” says Wesley Bronson, M.D., a spine surgeon and assistant professor in the Department of Orthopedic Surgery at Mount Sinai Health System in New York City. “If you’re driving a car and take your foot off the gas, that lifting of your ankle is primarily the responsibility of those two nerves. If you were to curl your toes down and then bring them back up, those two nerves are responsible for that, too.”

How Sciatica Causes Drop Foot

Now for the sciatica tie-in: The large sciatic nerve is made up of the L4 and L5 nerves. It travels from the spinal cord down the thigh before dividing into two branches. One of these branches is the peroneal nerve, which runs along the outside of the lower leg (below the knee) and branches off into each ankle, foot, and first two toes. It transmits signals to muscle groups responsible for ankle, foot, and toe movement and sensation.

So if your sciatic nerve is damaged, the signals transmitted to the peroneal nerve, and then your foot, can also be disrupted. “Drop foot can be caused by the same problems that can cause any symptoms of sciatica,” says Dr. Bronson. “Anything that leads to pressure on that nerve can give you a drop foot.”

Other Conditions That Cause Drop Foot

Several conditions can create sciatic nerve pressure, including lumbar disc herniation, spondylolisthesis, and spinal stenosis. These include:

• Infection

• Medical conditions such as a tumor or stroke

• Neuromuscular diseases such as amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), Parkinson’s disease, Guillain-Barré syndrome, and muscular dystrophy

• Peroneal nerve irritation during hip or knee replacement

In addition, traumatic injuries such as gunshot wounds, lacerations, and fractures in the leg or back can lead to the disorder.

Early Signs of Drop Foot

At first, you might have just felt like something was a little off with the way you were walking or your balance. But as drop foot progresses, you’ll likely notice a more significant limp or drag in one of your feet. “People with an early drop foot may notice lack of coordination or balance, particularly on one side,” says Benjamin T. Bjerke, M.D., an orthopedic surgeon in Jeffersonville, IN. “They also may trip when going over small clearances such as carpeting, curbs, or steps.”

There are several other signs of drop foot. These include:

• Numbness of the top of the foot

• Trouble holding onto footwear, especially flip-flops or shoes without backs

• Weakness when lifting the foot at the ankle

Drop Foot Gait

If you have drop foot, something so basic that you took it for granted—walking—suddenly become a challenge due to the inability to control your foot at the ankle. Your foot may appear floppy and you may begin to drag the foot and toes while walking. To compensate for these things, you may find yourself walking with an exaggerated or high step, called steppage gait or footdrop gait.

“Patients with a ‘drop foot’ or ‘foot drop’ usually have weakness in both the ability to lift up (using the tibialis anterior muscle) and turn out the ankle (using the peroneal muscles),” says Dr. Bjerke. As a result, “many patients will consciously or subconsciously step higher with the affected leg, known as a ‘steppage gait.’”

Dr. Bronson adds that when people with foot drop walk on uneven ground, they “don’t want to let their toes touch the ground because they’ll trip, so they bend at the hip and bend at the knee to bring their foot particularly high to clear the ground.”

Tests for Drop Foot

While symptoms of the disorder are usual visible by watching someone walk, to understand what is causing your drop foot, your doctor may want to run several tests to reach a diagnosis. These include:

• Blood tests

• Electromyography (EMG) and nerve conduction velocity (NCV) studies

• Imaging tests such as MRI, X-ray, or CT scans

• Nerve ultrasound

Drop Foot Treatment

Treatment focuses on addressing the underlying cause. Possible treatments include medications for neuromuscular disorders, surgery for lumbar spine abnormalities, addressing fractures and other trauma, and control of diabetes. There are also other options available to your health care provider.

Braces

If your drop foot is significant, your doctor may recommend an ankle foot orthosis (AFO), brace, or splint that fits into the shoe to stabilize your ankle or foot. One type of AFO is custom-made of stiff plastic. Your heel fits into a cup and there is a molded length of plastic going up the back of the leg as well as under the foot. This keeps the ankle in an “L” position, which prevents the foot from “dropping” down.

Physical Therapy

Specific exercises can help you regain some control over muscles in your lower leg and foot, something a physical therapist can teach you. Gait training may also be incorporated: In this instance, a therapist will teach you a safe, modified gait to help you avoid trips or stumbles.

Functional electrical stimulation (FES) is another physical therapy tool that has been used for years to treat drop foot. While walking, an electrical current is applied to the shin muscles. Much like a nerve impulse, this triggers the foot to raise up toward the lower leg (dorsiflexion). The advantages of FES-assisted walking are improved speed, step length, stability, and mobility.

Physical therapy is also helpful to address weakness, muscle stiffening, and stiffness. Exercises correct the range of motion in the ankle as well as strengthen the lower leg. This improves stability and control.

Depending on what has caused the nerve damage leading to drop foot, it may take months for the nerves to recover, so a dedicated home exercise program is important. These are some of the exercises your physical therapist may prescribe for you to do at home.

Foot Drop Exercises

Assisted toe raises:

1. Sit on a chair with both feet on the ground.

2. Place the affected foot on top of the other foot.

3. Pull the affected foot upward toward the body using the unaffected foot to “assist.”

Ankle abduction and adduction:

1. Sit in a chair with both feet on the ground.

2. Keep the affected foot flat on the floor with the heel stable.

3. Slide the foot left and right in a “windshield wiper” motion.

Ankle eversion and inversion:

1. Sit in a chair with both feet flat on the floor.

2. With the affected foot, roll the ankle outward so the foot is resting on its outer edge. 3. Then roll the ankle inward so the foot is resting on its inner edge.

Single leg stands:

1. Find a stable surface such as the back of a chair or countertop for support if needed.

2. Lift the unaffected leg and stand only on the affected leg for at least 10 seconds, increasing the amount of time as you become able.

Ankle dorsiflexion for range of motion:

1. Sit on a chair or the floor if you are able.

2. Loop an exercise band or towel around the bottom of the affected foot.

3. Pull the towel or band back toward the body causing the foot/ankle to flex up.

Ankle dorsiflexion for strengthening:

1. Sit on the floor if able.

2. Secure an exercise band around a chair or table leg.

3. Loop the band over the top of the affected foot.

4. Slowly pull the toes up toward the body, creating tension on the band.

Surgery for Drop Foot

Surgery may be necessary to correct or alleviate the underlying problem causing drop foot. For example, if drop foot is caused by nerve compression from a lumbar herniated disc, then a spinal surgical procedure called discectomy (disc removal) may be required to remove the pressure or ‘decompress’ the nerve.

Surgery is also used for spinal tumors and fractures or injuries of the peroneal nerve at the level of the knee.

Tendon transfer surgery takes a working tendon and stronger muscle from one part of the foot and moves it to another part of the foot. This compensates for the nerves and muscles that aren’t working properly.

In the case of permanent drop foot, ankle fusion surgery may improve function. The ankle bones are fused solidly together, preventing any motion at the ankle. This can improve gait and stability (although limiting mobility).

Ultimately, whether your drop foot is caused by sciatica or another health condition, addressing the underlying issue is the only way to get your usual gait or stepping pattern back. Fortunately, there are many treatments available to improve and even heal drop foot. Talk with your doctor about your options, so you can come up with a plan that works best for you.