Drop foot, also known as foot drop or dropped foot, is a symptom of a medical condition that makes it difficult to lift the front of the foot and the toes. Drop foot can be caused by conditions that lead to muscle weakness (for example, muscular dystrophy), peripheral nerve disorders (for example, neuropathy) or disorders of the central nervous system (NHS Choices 2014). Central nervous system disorders can be categorised into lower or upper motor neurone lesions, depending on the place within the neural pathway that has been damaged. The NICE guidance on functional electrical stimulation for drop foot of central neurological origin notes that upper motor neurone lesions often result from conditions such as stroke, multiple sclerosis, cerebral palsy or spinal cord injury. Depending on the cause, drop foot may affect one or both legs, and can either be temporary or permanent (NHS Choices 2014).
Drop foot lessens ankle stability and causes the person to drag their foot during walking, which is very tiring. This reduces mobility and may limit everyday activities, including going to work. People with drop foot may need walking aids or wheelchairs to keep mobile. It also increases the risk of trips and falls, which can lead to the person needing formal care and even hospital admission (Wilkinson et al. 2014). So, the treatment of drop foot is important to ensure people can remain mobile and live independently.
Drop foot is commonly a secondary and unreported symptom of a medical condition, so the prevalence is difficult to estimate. Over 65% of people with multiple sclerosis (about 57,000 people living with the condition in England) experience some mobility problems (Jones et al. 2013; Multiple Sclerosis Society 2016) and about 72% of people surviving stroke (approximately 707,000 people in England) are affected by leg weakness (Lawrence et al. 2001; Stroke Association 2016), which may lead to drop foot.