Functional Electrical Stimulation
National Clinical FES Centre
Salisbury District Hospital
Salisbury, Wiltshire, SP2 8BJ
Functional Electrical Stimulation
Functional Electrical Stimulation (FES) can help people who have had damage to their brain or spinal cord to move more easily. This information leaflet explains what is meant by FES, who may benefit and how. It gives information about what FES treatment involves and how to find out more about it.
What is Functional Electrical Stimulation?
It is using small electrical impulses to activate paralysed muscles and so produce useful movement. The electrical impulses work by exciting the nerves leading to the muscles. Self-adhesive patches (electrodes) are usually placed on the skin close to the nerve supplying the muscle; this is often over the centre of the muscle. Leads connect the electrodes to a stimulator that produces the impulses.
Who may benefit from using FES?
People who have difficulty moving due to damage to their brain or spinal cord such as from a stroke, suffer from Multiple Sclerosis (MS) or have had an incomplete spinal cord injury (T12 or above). It can sometimes be used with children who have cerebral palsy and people who have had a head injury. To be effective it is important that the nerve fibres between the spinal cord and the muscles are not damaged. The impulses need to travel along the nerves to reach the muscles.
How FES can help walking
The most common problem treated by FES is called dropped foot. This is an inability to lift the foot and toes when swinging the leg during walking, causing the toes to catch or the foot to drag on the ground. Dropped foot is caused by weakness of the muscles that lift the foot and excessive tightness (spasticity) in the muscles of the calf. Stimulation is given to the muscles at the front of the leg. The simplest stimulator is the Odstock Dropped Foot Stimulator (ODFS). It activates the muscles that lift the foot during walking. A switch worn in the shoe triggers the stimulation and electrical signals reach the muscles through electrodes stuck to the skin on the side of the leg, just below the knee. The stimulator is about the size of a pack of cards and can be worn at the waist on the belt or in a pocket. Leads connect the stimulator to the switch in the shoe and the electrodes on the leg. A small battery operates the stimulator.
Electrical stimulation can help people to walk faster, with less effort and with more confidence. Stimulators are continuing to be developed, computer technology is allowing them to be more finely controlled and more muscle groups can be stimulated to produce a more natural walking pattern.
How stimulation can be used to improve arm and hand function
This is much more varied and complicated. Stimulation may be given as a sort of exercise to strengthen weak muscles or relax tight ones. Sometimes the patient or their therapist, using a foot pedal or other device, controls the stimulation. This sort of stimulation is often used as part of physiotherapy. People who benefit from this usually already have some movement of the arm and hand: FES is used to improve on this in order to make the hand and arm more useful.
Are there any tests involved?
Tests are usually performed to measure walking speed and effort, or quality of movement. Patients who are using stimulation to improve arm and hand function may be asked to perform a simple functional test. Tests rarely take longer than an hour and are repeated at regular intervals to measure progress and to find out whether treatment needs to be changed.
Are there any risks or side effects?
Stimulation causes a tingling "pins & needles" sensation on the skin, although most people do not find it uncomfortable, a few do and for this reason do not use it. Sometimes even though patients are carefully assessed, we find that treatment has not helped them or that they are unable to use the stimulator effectively. In these cases, stimulation will be stopped. Very occasionally, patients find the electrodes irritate their skin. Using hypoallergenic electrodes or changing the type of stimulation used can often solve that problem. Very rarely we have found that stimulation increases muscle tightness (spasticity) and in these cases treatment will be stopped.
What are the benefits of treatment?
Clinical trials and measurements taken with patients who have used FES to help their walking have shown that they are able to walk faster, with less effort and with more confidence when the use the stimulator. Sometimes muscle tightness is reduced. Some patients have found that after using the stimulator for a few months their walking is sufficiently improved that they no longer need to use it.
How do patients get FES treatment?
Patients should contact their GP or hospital consultant who will refer them to us if there is a possibility that FES may help. Therapists, doctors, or other health professionals who have patients who may benefit should contact Professor Ian Swain, or a member of the team directly at the Department of Medical Physics & Biomedical Engineering, Salisbury District Hospital, for an initial assessment.
What does treatment involve?
Patients are assessed by a physiotherapist and a clinical engineer to see whether FES would benefit them. Clinics are held on Friday afternoons in the Medical Physics & Biomedical Engineering Department at Salisbury District Hospital. An assessment takes about one hour. If we judge that we can help we report this to the referring Doctor. Appointments are then made for the patient to attend the clinic to start treatment. Two appointments, usually on consecutive days, are normally needed to set up a stimulation programme. Further appointments are made so that progress can be measured and adjustments made to the stimulator or exercise programme. Treatment is given by a physiotherapist or a clinical engineer who has been specially trained in using FES. Some patients use stimulation independently everyday others use it a part of their physiotherapy treatment. Some patients continue to use FES for many years, others only for a period of a few months.
Is treatment only available at Salisbury District Hospital?
We actively encourage clinics in other hospitals around the country.
For more information please contact:
Ian Swain, Paul Taylor or Geraldine Mann, Odstock Medical, Salisbury District Hospital
Salisbury, Wiltshire SP2 8BJ
Tel: 01722 429065
Fax 01722 425263
You can find out more about FES from our website: www.odstockmedical.com
ã Salisbury Health Care NHS Trust