In all of healthcare, there is probably no condition whose name it is easier to remember than Foot Drop.
Foot Drop is a condition that is quite literally described by its name – a person’s foot drops. A person suffering from this condition is unable to raise their foot at the ankle – ask them to walk on their heels and their foot remains stubbornly flat on the ground.
Being asked to walk on one’s heels is a routine part of the examination for anyone with suspected nerve injury in their legs. It does sound like a very odd request for the doctor to make, and often earns the physician a disbelieving look from the patient. However, that look may change greatly when the patient realises for the first time that they are unable to lift their foot.
This lack of control over the foot can have profound effects on the ability to walk. Many of us taking walking for granted, and do not realise that the walking cycle is much more than just swinging one leg after the other. Among many other coordinated acts of the body during walking, the feet undergo very controlled movements.
Obviously then, Foot Drop creates problems with the normal walking cycle. When the swinging leg is brought forward, the toes inappropriately point down and may drag on the ground. To compensate for the toe dragging people with Foot Drop exhibit an exaggerated or high-stepping walk called Steppage Gait.
Sometimes the foot and leg are brought forward so high, that the foot then slaps down on the ground. This is called Foot Slap, and is another clue for the physician about possible Foot Drop.
Steppage Gait and Foot Slap are carefully watched for by the physician during the examination. Interestingly, a person with Foot Drop will still be able to walk on the balls (toes) of their feet. The muscles that push the foot down are controlled by a different nerve.
The culprit for Foot Drop is usually injury of the peroneal nerve. The peroneal nerve is one of the end branches of the sciatic nerve. The peroneal nerve runs along the outside of the lower leg below the knee. The peroneal nerve transmits signals to muscle groups responsible for certain movements of the ankle, foot, and toes. The peroneal nerve is also responsible for sensation, so suffers of Foot Drop may also complain of pain and numbness along the course of the nerve.
Unfortunately the peroneal nerve is susceptible to injury from a variety of sources, which can make diagnosing the cause of Foot Drop difficult. Foot Drop can be the end result of neurological injury anywhere from the brain to the knee. Foot Drop can also occur on occasion as part of Amyotrophic Lateral Sclerosis (ALS), Multiple Sclerosis (MS), and Parkinson’s disease.
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.