Foot drop is a condition that is familiar to many people. It is an issue with the nerves where the toes and mid-foot have poor control for lifting the foot. It can occur in one foot, but it can appear on both feet, depending on the source of the issue.
Foot drop affects walking as the toes drag, making it easy to trip and stumble. To be able to walk, individuals must lift their thigh extra excessively to make sure their foot is high enough to make the step. When the foot is placed back on the ground, it can land flat or at an angle, creating more issues of muscle strains and bone fractures. The foot can also be pointed outward when standing. There can be pain in the calf, lower leg, ankle, and toes. Toes can be numb. Generally, the foot exhibits weakness.
Those who have mobility issues that prevent them from walking can have the consequences of foot drop. This can include difficulty positioning, skin breakdown, and shortening of the Achilles tendon or other anatomical issues.
Anyone with or without the disease can acquire a foot drop. Individuals with nervous system injury can have weak muscles and nerves, which can lead to the issue. People with no neurological issues who sit with their feet unsupported can develop it. An example is sitting in a recliner where the footrest does not extend to the back of the heel. If the footrest ends at the back of the ankle, over time, the weight of the foot can cause the foot to extend straight out from the leg instead of at a 90-degree angle. Individuals who have been ill and have been in bed for even a short time can get foot drop from not exercising the ankle joint. Even the weight of a sheet or blanket can weigh down a foot to the straight position. In other words, anyone can get foot drop. Foot drop can be temporary or permanent.
The National Institute of Neurological Disorders and Stroke (NIH) lists these issues as related to foot drop. I have added a few additional risks. If you have one of these issues, you may not develop foot drop, but you are at risk.
The peroneal nerve in the leg is a common cause of foot drop due to compression or damage. This nerve passes behind the knee extending around the shin. Crossing your legs, pressing the side of your leg against something, or sitting with your leg under your body can lead to peroneal compression. Squatting or kneeling can put pressure on the peroneal nerve. A cast that is too tight can constrict the nerve. Truckers sometimes have compression issues with the peroneal nerve if they rest it against the gearbox in the truck on the right side or against the door on the left side for long periods of time.
Diagnosing foot drop is fairly easy just by looking at the foot. Still, a complete physical assessment is conducted, including observation of gait and evaluating muscle strength and sensation, especially on the top of the foot, toes, and shin. You will be asked about a history of how long this has been occurring if you have engaged in any activity, injuries or postures that could compress the peroneal nerve.
Blood work may be done to look for underlying medical issues such as diabetes, infection, or alcohol abuse, which can affect your nerves.
Imaging studies will indicate the location of the injury. The source of the issue could be as high as in the spine or anywhere along the route of the leg nerves. These studies may include CT scans, MRI, ultrasound, or even an x-ray to assess the tissue and nerves that could be the source of the problem. An assessment of swelling of the nerves or swelling around the area of the nerves or compression due to soft tissue injury or tumor is made.
Nerve testing will provide information about how well your nerves are functioning or transmitting messages. This includes electromyography (EMG), which measures muscle function and nerve conduction studies (NCS), an assessment of nerve function. These assessments are conducted by application of a mild electric current either through a needle in your skin or by use of an electrical patch.
Treatments for foot drop will aim at the cause. Depending on your situation, you may use some of these options to improve your situation. Not all cases of foot drop can be cured depending on the cause, but there are many options that can help.