Functional Electrical Stimulation

Functional Electrical Stimulation (FES) can be used to help people who have had a stroke to lift their foot when walking. This was first done in 1960 by American bioengineer called Liberson. For some time after this the idea was not developed, mainly because the technology was neither reliable nor user-friendly.

During the last eight years research at Salisbury District Hospital, in conjunction with Surrey University in Guildford, Kings College London, and more recently Southampton University has made FES much more effective and useful.

The people most likely to benefit are those who have a drop-foot that causes them to either trip or hitch their hip when they walk. It is not suitable for people who are unable to walk. Work is also being done to apply the techniques to arm problems and it seems to be useful with people who have some arm function but who, for example lack the ability to open the hand even though they have quite a good grip.

The principle of FES is to replace the nerve impulses to the muscles that are interrupted by damage to the brain or spinal cord with small electrical signals. It can be used not only with people who have had a stroke, but also people with spinal cord or head injuries, MS or cerebral palsy. It seems that it is particularly useful when people have spasticity - muscle stiffness.

The simplest stimulator is one that activates the muscles that lift the foot during walking. A switch worn in the shoe triggers the stimulation and the 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.

Research has shown that when stimulation is effective the person can 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.

This diagram below shows the path of the common peroneal nerve that supplies the muscles that lift the foot. It has two branches; one to the front of the leg, supplying the muscles that lift the foot and turn it slightly inwards, and one on the outer side of the leg supplying the muscles that turn the foot outwards (eversion). Precise positioning of the electrodes produces a natural ankle movement when the leg is swung forward during walking. The diagram shows the most commonly used electrode position.

Picture of leg muscles

If on reading this you think that you may benefit from FES, you should contact your GP or hospital consultant. If they feel you may be suitable they can refer you to me, Jane Burridge, at the Department of medical Physics, Salisbury District Hospital, for an initial assessment. The normal procedure is for patients to be assessed here to see whether FES would be of benefit to them.

Clinics are held every Friday and an assessment takes about one hour. If we judge that we can help we report this to the Doctor who referred you and make appointments for you to attend the clinic, usually on two consecutive days, for a stimulator to be set-up. We then check your progress at regular intervals to ensure things are working well and to measure your progress.

Alternatively, to find out more, contact me directly or visit our website -- details are at the end of this article.

With the increase in demand for this treatment we have set up a few clinics at other specialist units around the country -- in London, at Kings College Hospital, Birmingham and elsewhere, so it may not be necessary for you to travel to Salisbury.

Useful addresses:

You can find out more about FES from our website:
www.salisburyfes.com

If you do not live in the Salisbury area it is possible that you could be seen at one of our satellite clinics or by the FES clinic in Birmingham. The person to contact there is


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