Common Peroneal Neuropathy

The Peroneal nerve is on the outside of the fibula just below the knee. Pressure to the peroneal nerve, as you might experience if you sit with your legs crossed for too long, can trigger temporary foot drop.

Foot drop, sometimes called drop foot, is a general term for difficulty lifting the front part of the foot. If you have foot drop, you may drag the front of your foot on the ground when you walk. Foot drop isn’t a disease. Rather, foot drop is a sign of an underlying neurological, muscular or anatomical problem. Sometimes foot drop is temporary. In other cases, foot drop is permanent. If you have foot drop, you may need to wear a brace on your ankle and foot to hold your foot in a normal position Of drop makes it difficult to lift the front part of your foot, so it might drag on the floor when you walk. To counter this, you might raise your thigh when you walk, as if you were climbing stairs (stoppage gait), to help your foot clear the floor. This odd gait might cause you to slap your foot down onto the floor with each step you take. In some cases, the skin on the top of your foot and toes may feel numb. Foot drop typically affects only one foot. Depending on the underlying cause, however, it’s possible for both feet to be affected Foot drop is caused by weakness or paralysis of the muscles involved in lifting the front part of the foot. The underlying causes of foot drop are varied and may include:

1. 1. Nerve injury. The most common cause of foot drop is compression of a nerve in your leg that controls the muscles involved in lifting the foot. This nerve can also be injured during hip or knee replacement surgery, which may cause foot drop. A nerve root injury (“pinched nerve”) in the spine can also cause foot drop. People who have diabetes are more susceptible to nerve disorders, which are associated with foot drop.

1. 1. Muscle or nerve disorders. Various forms of muscular dystrophy, an inherited disease that causes progressive muscle weakness, may contribute to foot drop. Other disorders, such as polio or Charcot-Marie-Tooth disease, also can cause foot drop.

1. 1. Brain and spinal cord disorders. Disorders that affect the spinal cord or brain — such as amyotrophic lateral sclerosis (ALS), multiple sclerosis or stroke — may cause foot drop

1. 1. The Peroneal nerve controls the muscles that lift your foot. This nerve runs near the surface of your skin on the side of your knee closest to your hand. Activities that compress this nerve can increase your risk of foot drop. Examples include:

1. 1. Crossing your legs. People who habitually cross their legs can compress the peroneal nerve on their uppermost leg.

1. 1. Prolonged kneeling. Occupations that involve prolonged squatting or kneeling — such as picking strawberries or laying floor tile — can result in foot drop.

1. 1. Wearing a leg cast. Plaster casts that enclose the ankle and end just below the knee can exert pressure on the peroneal nerve.

Of drop is usually diagnosed during a physical exam. Your doctor will want to watch you walk and may check a number of your leg muscles for weakness. He or she may also check for numbness on your shin and on the top of your foot and toes. In some cases, additional testing is recommended.

Imaging tests

1. 1. Foot drop is sometimes caused by an overgrowth of bone in the spinal canal or by a tumor or cyst pressing on the nerve in the knee or spine. Imaging tests can help pinpoint these types of problems.

1. 1. X-rays. Plain X-rays use a low level of radiation to visualize a soft tissue mass or a bone lesion that may be causing your symptoms.

1. 1. Ultrasound. This technology uses sound waves to create images of internal structures. It may be used to check for cysts or tumors that may be pressing on the nerve

1. 1. Computerized tomography (CT) scans. Computerized tomography combines X-ray images taken from many different angles to form cross-sectional views of structures within the body.

1. 1. Magnetic resonance imaging (MRI). This test uses radio waves and a strong magnetic field to create detailed images. MRI is particularly useful in visualizing soft tissue lesions that may be compressing a nerve.

1. 1. Nerve tests Electromyography (EMG) and nerve conduction studies measure electrical activity in the muscles and nerves. These tests can be uncomfortable, but they’re very useful in determining the location of the damage along the affected nerve.

1. 1. Treatments and drugs

1. 1. Treatment for foot drop depends on the underlying cause. If the underlying cause is successfully treated, foot drop may improve or even disappear. If the underlying cause can’t be treated, foot drop may be permanent.

1. 1. Specific treatment for foot drop may include:

1. 1. Braces or splints. A brace on your ankle and foot or splint that fits into your shoe can help hold your foot in a normal position.

1. 1. Physical therapy. Exercises that strengthen your leg muscles and help you maintain the range of motion in your knee and ankle may improve gait problems associated with foot drop. Stretching exercises are particularly important to prevent the development of stiffness in the heel.

1. 1. Nerve stimulation. Sometimes stimulating the nerve that lifts the foot improves foot drop.

1. 1. Surgery. Depending upon the cause, and if your foot drop is relatively new, nerve surgery may be helpful. If foot drop is long-standing, your doctor may suggest surgery that fuses ankle or foot bones or a procedure that transfers a functioning tendon to a different position.

1. 1. Because foot drop can increase your risk of tripping and falling, you might want to take these precautions around your house:

1. 1. Keep all floors clear of clutter.

1. 1. Avoid the use of throw rugs.

1. 1. Relocate electrical cords away from walkways.

1. 1. Make sure rooms and stairways are well lit.

1. 1. Place fluorescent tape on the top and bottom steps of stairways.