Foot drop – what is it and what therapies exist?

PhysioFunction is supporting National Foot Drop Awareness Day on September 22. Here, the team tell us more about foot drop and therapies that can support with that

Foot drop is defined as “an inability to lift the forefoot due to the weakness of dorsiflexors of the foot” (Nori & Stretanski, 2022). It has multiple potential causes, from lumbar nerve root compression, spinal cord injury, peripheral nerve injury, or dysfunction of the central nervous system (such as cerebrovascular accident/ stroke), peripheral nervous system (such as Guillian-Barre Syndrome) or both (such as motor-neurone-disease). Following stroke, a foot drop gait is common, affecting 20 to 30 per cent of stroke survivors (Peishun et al., 2021). 

Typically, a foot drop gait presents in difficulty clearing the toes from the ground during gait, requiring compensatory movements at the knee, hip and lower back on the same side, as well as increased weight transfer and an asymmetrical movement pattern, which results in an inefficient gait pattern, reliance on walking aids and an increased risk of falls.

Despite its common occurrence and recognisable presentation, foot drop is often poorly managed, which can have profound consequences on the individual, such as reduced participation in physical activity, reduced social integration, and complications after falls.

There are two primary modes of managing foot drop once the cause has been determined. The first of these is the Ankle-Foot Orthosis (AFO). An AFO can come in many forms, from elasticated straps to raise the toes, to solid and moulded thermoplastic splints and lightweight carbon supports. The correct solution is highly individual and is identified after careful evaluation of the cause of their foot drop, any associated symptoms (such as ataxia or spasticity) and their level of activity. Burns et al. (2021) reported that the use of an AFO in people with foot drop due to Multiple Sclerosis resulted in reduced fatigue, improved gait, reduced trips and falls, increased participation, increased confidence and greater balance/stability.

The second is the use of function electrical stimulation (FES). FES involves the application of an electrical current from the surface of the skin close to the nerve that activates the dorsiflexors of the ankle (the common peroneal or common fibular nerve) causing the nerve to depolarise and create a contraction in the dorsiflexor muscles. Due to the ‘active’ nature of FES (i.e. the device activates the body to generate movement), the common fibular nerve, and its proximal root the sciatic nerve, must be at least partially intact. For this reason, FES is primarily used in conditions where the foot drop is a result of dysfunction in the central nervous system, i.e. the brain and spinal cord. In some instances, foot drop due to peripheral, or mixed central and peripheral nervous system impairment, can effectively respond to FES provided there is sufficient capacity within the nerve to carry the signal.

A nerve conduction study, or stimulation response test may be used in such cases to determine suitability for the use of FES. Traditional devices involve the application of adhesive electrodes, connected by wires to a control box and foot switch, which have been reported to be challenging for reliable placement on each occasion. Modern devices use a cuff with inbuilt or attachable electrodes to improve the consistency of the effect, as well as using inclinometers and gyroscopes to trigger the stimulator at the correct point during gait. Burns et al. (2021) reported that in their focus groups of people with foot drop due to MS, the use of an FES foot drop stimulator resulted in similar improvements as the AFO for reducing fatigue, improving gait, reducing trips and falls, increasing participation and increasing confidence, and whilst they did not report as much improvement in balance and stability, there were reported improvements in walking distance, fitness and physical activity.

PhysioFunction have been an international leader in the clinical management of foot drop for two decades and offer a comprehensive service of assessment and provision of a wide range of AFO and FES based foot drop. In particular, we champion the use of FES solutions, working directly with the Bioness L100 and 300 GO systems, and Walkaide II, and for those where an AFO is indicated, the Turbomed range of dynamic orthotics. Combining the use of aids with hands-on physiotherapy and exercise rehabilitation using our Rehabilitation Triad, we work with our clients to optimise rehabilitation and maximise function.

This year 2023, National Footdrop Society (NFDS) are holding their annual awareness day on September 22. This is timed to coincide with the start of fall (autumn) on September 23.

This year we are collaborating with Blatchford at our Spratton clinic and we will be offering foot drop assessments for both the FES devices and Turbomed devices. If you would like an in-person assessment, please contact rehab@physiofunction.co.uk to book in.