What is Foot Drop?

The term foot drop describes a condition that presents a limp like, weak foot that causes difficulty when walking. With foot drop, also interchangeably called drop foot, a person loses the ability to raise the foot at the ankle. The condition causes the person to lift the afflicted foot high to allow the toes to clear the ground; this is known as steppage gait.

Some cases of foot drop are temporary and others are permanent. Causes of foot drop are numerous, but the most common cause is an injury to the peroneal nerve at the top of the calf behind the knee and after hip surgery. Other causes of foot drop include, Charcot Marie Tooth Disease (CMT) multiple sclerosis, Parkinson's disease, amyotrophic lateral sclerosis (ALS) Lou Gehrig's disease, and muscular dystrophy. Additional causes include stroke, drug toxicity, diabetes, low back pain, and cauda equine, a compression of the lower bundle of nerves in the spinal cord.

Peroneal nerve palsy is the term used when the nerve at the top of the calf behind the knee is compressed. If the peroneal nerve is injured, it cannot support the tibialis anterior, the muscle which lifts the foot. To diagnose foot drop, a physician will take a complete medical history and may order tests such as magnetic resonance imaging (MRI) or an electromyogram (EMG).

There are shoes and straps that can mimic the natural ankle motion and help patients with foot drop. An ankle-foot orthosis is a brace, generally made of plastic, which supports the ankle and holds the foot and ankle in the correct position. These can be cumbersome, cause skin irritation and difficult to fit in a shoe. Surgical treatment is also an option and can involve decompression, and or muscle tendon transfer techniques to move strong healthy tendons to take the place of those that are not functioning properly.