The National Institute of Neurological Disorders and Stroke, National Institutes of Health, defines foot drop as “the inability to raise the front part of the foot due to weakness or paralysis of the muscles that lift the foot.” Muscles in the leg cannot raise the foot at the ankle, or the front part of the foot, due to paralysis of muscles that lift the foot.
Consequentially, people who have foot drop scuff their toes along the ground; they may also bend their knees to lift their foot higher than usual to avoid the scuffing, which causes what is called a “steppage” gait. When caused by pressure on the nerves that control the muscles in the leg or by a knee injury, foot drop can be temporary. However, damage to the nerves — and other medical disorders — can cause this to be a permanent condition affecting one or both feet.
- Nerve injury: Compression of the nerve that controls the muscles involved in lifting the foot, which can happen at the knee or in the lower spine during hip or knee replacement surgery. Additionally, diabetic neuropathy (long-term nerve damage associated with diabetes) can also cause foot drop.
- Muscle or nerve disorders: Forms of muscular dystrophy (an inherited disease that causes progressive muscle weakness), polio or Charcot-Marie-Tooth disease can cause foot drop.
- Brain and spinal cord disorders: These include amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS) or stroke.
One neighbor experienced foot drop as the result of a stroke nearly one year ago. I hadn’t seen him in many months; he didn’t want to discuss it. I saw the stroke had affected his left side. While physical therapy helped him lift his leg, it looked like his foot and ankle muscles hadn’t fully recovered.
Toes that point away from the body when the foot is relaxed indicated foot drop. Feet and legs may feel weak; the person may have difficulty walking, or scuffs his or her toes, and trips frequently over the affected foot. To overcome or compensate, the person may lift the knees higher (step gait) so there is less chance of stumbling over the toes. The person may also slap his or her foot down with each step. In some cases, there may be tingling or numbness on the top of the foot, toes and ankle, caused by the particular way of walking, or it can be linked to an underlying cause of foot drop.
Foot drop is diagnosed during a physical exam. The doctor will ask you to walk and will check leg muscles for weaknesses and may check your shins and the tops of your feet and toes for numbness.
Specific causes of foot drop determine its treatment. Supporting the foot with light-weight leg braces and shoe inserts, called ankle-foot orthotics, is a commonly-used treatment; exercise therapy can strengthen muscles and maintain joint motion, which helps improve gait.
The peroneal nerve controls the muscles that lift the foot. Activities that compress this nerve, such as crossing one’s legs, prolonged kneeling or squatting, or wearing a leg cast, exert pressure on this nerve and increase risk of foot drop.
Electronically stimulating the peroneal nerve during foot fall can be appropriate for some people with foot drop. Surgery fusing the foot and ankle joint, or that transfers tendons from stronger leg muscles, is occasionally performed when there is permanent loss of movement.
Foot drop caused by trauma or nerve damage can show a partial or complete recovery; if a symptom of progressive neurological disorders, foot drop can continue as a lifelong occurrence and will not shorten life expectancy. Treatment depends on the underlying cause, which, if successfully treated, may improve foot drop or cause it to disappear.
Other helpful treatments include an ankle and foot brace or a splint, physical therapy and exercises that strengthen the leg muscles and help maintain knee and ankle range of motion; heel stiffness can be prevented by stretching exercise.
Due to increased risk of falling and tripping, caregivers are reminded to take precautions at home.
- keep floors clear of clutter
- avoid using throw rugs which can slip
- move all electrical cords from walkways and halls
- keep rooms and stairways properly lighted
- place fluorescent tape on the tops and bottoms of stairs