Foot drop does not happen on its own. It is typically caused by nerve damage, which can stem from several underlying causes. Foot drop dramatically affects gait, and this is often one of the first signs that someone has developed the condition. Foot drop can happen to anyone at any age. The underlying cause will generally determine the treatment.
What is Foot Drop?
A person with foot drop cannot lift the front part of one or both feet due to weakness or paralysis of the muscles required for this motion. Foot drop makes it difficult to walk normally because the individual’s toes slide along the ground. To compensate, the person must lift their knees higher when they walk. Foot drop can affect one foot or both feet and, as a symptom of an underlying problem, may be temporary or permanent depending on the cause.
Most Common Cause of Foot Drop
The most common cause of foot drop is nerve injury. The peroneal nerve controls the muscles that lift the foot; surgery on the knee or hip can damage this nerve. Damage to the nerves in the lower end of the spinal cord, called a nerve root injury, can also cause foot drop. In some cases, tumor or cyst growing in the spinal canal can lead to the symptom, as well.
Other Causes
Muscle or nerve disorders such as polio, spinal muscular atrophy, and muscular dystrophy can lead to foot drop over time because they cause progressive muscle weakness. Other disorders that affect the brain and spinal cord, including multiple sclerosis, stroke, and amyotrophic lateral sclerosis (ALS) may cause foot drop as well. Nerve damage from diabetes can also increase the chance of developing the condition.
Risk Factors
In addition to muscle and nerve disorders, other risk factors also increase the change of developing foot drop. The peroneal nerve sits near the surface of the skin on the outer side of the knee. If this nerve is damaged or compressed, foot drop can result. People who habitually cross their legs or kneel for long periods, or anyone who has worn a plaster cast below the knee, are at a greater risk of foot drop.
Diagnosis
Doctors can usually diagnose foot drop with a physical exam. If the doctor suspects the condition, he or she will assess the patient’s gait and may test for numbness on the top of the foot and shin. Imaging tests such as x-rays or CT scans can help pinpoint the problem, identifying masses or lesions. An MRI can highlight anything compressing the nerve, while an ultrasound checks for cysts or swelling.
Nerve Testing
An electromyography or EMG test measures the electrical activity in the nerves and muscles and is useful for pinpointing the damaged area of the peroneal nerve. While these tests can be uncomfortable, the results can help the doctor develop a focused treatment plan.
Treatment
Treatment for foot drop depends on the underlying cause. If treatment cures this issue, foot drop may resolve. If the cause cannot be treated, the secondary condition could be permanent. Interventions for foot drop include braces or splints to hold the foot in a normal position, physical therapy to strengthen leg muscles and improve gait, and surgery. New cases may be improved with nerve surgery, while long-standing cases may need surgery to fuse the ankle and foot bones. Nerve stimulation is also effective in some cases.
Living with Foot Drop
People with foot drop can make some lifestyle changes to make their day-to-day life simpler and safer. Because foot drop drastically affects gait, tripping and falling are considerable risks. Keeping floors free of clutter, removing throw rugs, hiding cords, and making sure stairways are well lit can help prevent injury.
When to See the Doctor
Early treatment can mean a better recovery, depending on the cause. If a person finds their toes are scraping the ground or they are required to make extreme swinging hip motions when walking, they should speak to a physician. Other signs of a larger issue include a limp foot, tingling or numbness in the foot, difficulty climbing stairs, and muscle atrophy in the leg.
New Advancements in Treatment
There have been some advances in the treatment of foot drop. New interventions are being developed to help improve gait. These devices work by sending a low level of electrical impulses through the nerve. Their success depends on both the underlying cause and the integration of other treatments such as physical therapy.