Foot drop describes the inability to properly lift the foot and big toe when walking. Children will compensate in many ways to help clear their foot when walking and may walk in such a way where their limb movements are not completely repeated in the same way on the other side of their body. Foot drop can be caused by a disruption of the neurological motor control pathway (the way the brain sends messages to the body) or when the muscles are not strong enough to lift the foot and toes. Foot drop is associated with numerous disabilities including cerebral palsy, stroke, spinal cord injury, multiple sclerosis and traumatic brain injury.
How is Foot Drop Treated?
The initial treatment for drop foot is usually physiotherapy that includes exercises and learning how to walk. Children may also be given an Ankle Foot Orthosis (AFO), a hard splint that keeps the foot at 90 degrees. Another option is trying Functional Electrical Stimulation (FES). This treatment uses the application of small electrical charges to stimulate the nerves, which connect to the affected muscle. FES can be used on lots of different nerves in the body but for foot drop, the peroneal nerve, on the outside part of the lower knee, needs to be targeted. Electrodes are applied to the skin over the nerve, and for children, this is normally applied via a cuff that is worn below the knee. When the current is applied it feels a bit like pins and needles. A pressure sensitive switch in the shoe activates the device, so that when the foot is lifted and the pressure is taken off, the sensor causes the electrode to send an impulse through the nerve. This activates the muscles in order to help lift the foot up. When the foot is then placed on the ground and the pressure is reapplied to the sensor the impulse stops. FES therefore helps to produce a more normal walking pattern that is more efficient and more balanced.
The Magic of Functional Electrical Stimulation
FES applies impulses along the existing nerves, so the nerve fibres between the spinal cord and the muscles they supply, must be undamaged in order for it to work. The child also needs to be able to walk a few steps with or without a walking aid. A physiotherapist will be able to assess your child and make recommendations as to whether or not your child would benefit from such a device. If your child is a suitable candidate, then the physiotherapist will be able to set up the device and start walking re-education with your child. This will involve using the FES in conjunction with physiotherapy exercises, and will allow your child to build up strength and range of movement.
If your child has a foot drop and you think they may benefit from the use of an FES device then please call our team to arrange an assessment.
Post by Victoria Healey, Head of Paediatric Physiotherapy at Physiocomestoyou.