The term “foot drop” may seem simple, but it describes an often-complicated condition in which the foot is unable to elevate at the ankle, resulting in difficulty walking and a floppy appearance. Foot drop is caused by a number of factors, but one important factor is damage to the nerves controlling the leg muscles that bend and lift the front part of the foot and toes.As a result, people either drag their feet and toes or walk with high steps referred to as the ‘steppage’ gait.Foot drop often leads to pain or discomfort neurological symptoms, such as tingling or burning. This way of walking requires more effort and in time may lead to other problems, such as back or hip pain.
The peroneal nerve is a group of muscles that runs from the back of the knee around to the front of the shin and provides movement (motor control) and sensation to the lower leg, foot, and toes.Moreover, as this nerve supplies the tibialis anterior muscle (TAM), which lifts the foot, any damage disrupting the motor control pathway between the peroneal nerve and TAM can result in foot drop.Consequently, the peroneal nerve can be damaged by injuries such as sports injuries, gunshot wounds, hip replacements, childbirth, or diabetic complications as it lies close to the surface of the skin.Foot drop can also be caused by multiple sclerosis, a stroke, spinal cord damage, or cerebral palsy.
Handling foot drop ups and downs
Figure 1: The incision at the popliteal fossa.
The extent and cause of foot drop determine the types of treatment available. An orthosis (ankle-foot orthosis) can be fitted to help support the foot and improve walking ability, but many users find them uncomfortable and unhygienic.
Nerve stimulators, which apply small electrical charges to the leg, can help some patients gain more mobility. If the nerve does not recover, surgical treatment may be considered. Peroneal nerve decompression is an option for compressed nerves, or tendons may be transferred from one leg to another.In general, however, foot drop is difficult to treat successfully due to the small size of the nerve that is involved (less than 6cm). Nerve grafting is therefore a limited treatment option.
