COVID-19 restrictions to remain in place at The Walton Centre

Restrictions remain in place across the NHS in relation to the COVID-19 pandemic. The safety measures in place over the 18 months therefore remain in place at The Walton Centre - and in our other clinic settings within the community – until further notice.

Due to the increased transmission risk posed by the Omicron variant, visiting has been suspended within The Walton Centre except for exceptional circumstances.

Multiple Sclerosis - Functional Electrical Stimulation

Firstly, please read the following list of other medical conditions/circumstances and if you think any of these apply to you CONTACT 0151 556 3742 BEFORE attending your FES Clinic appointment.

Do you have:

  • A cardiac pacemaker inserted
  • Any metal pins or plates in the leg that is to be treated with FES
  • Any severe problems with skin allergies or very poor skin sensation on the leg to be treated
  • Any problems with severe swelling in the leg lasting more than a few days at a time on the leg to be treated
  • Currently or in the past a deep vein thrombosis (blood clot) in the leg
  • Any trauma to the nerves in the legs (other than the MS related nerve problems)
  • Epileptic fits
  • For females, do you intend to become or are you pregnant

Please complete the form at the end of the pack with your details and information. This will allow us to proceed with your examination at clinic efficiently. This information will be stored confidentially with your FES notes. If you have any questions please contact us as soon as possible before attending your appointment.



Functional Electrical Stimulation (FES) can help people who have had damage to their brain or spinal cord to move more easily. This fact sheet explains what is meant by FES, who may benefit and how. It also describes the process that will happen to you in FES Clinic over the next few months.

What is FES?

FES has been used widely in rehabilitation for therapy, function restoration and maintenance of vital function in muscle weakness and/or paralysis. FES uses small electrical impulses to activate muscles by exciting the nerves leading to the muscles. Two self-adhesive patches (electrodes) are usually placed on the skin close to the nerve supplying the muscle and over the centre of the muscle. Leads connect the electrodes to an electrical stimulation box which contains a battery and that produces the impulses. Another lead connects the box to a small pressure switch worn inside the shoe. The stimulator is about the size of a pack of cards and can be worn at the waist on a belt or in a pocket. Leads connect the stimulator to the switch in the shoe and to the electrodes on the leg. A small 9V battery operates the stimulator.

Who may benefit from using FES?

People who have difficulty moving due to damage to their brain or spinal cord, such as people with MS can benefit from FES.

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/or excessive tightness (spasticity) in the muscles of the calf. Stimulation is given to the muscles at the front of the leg. The simplest stimulators are the Odstock Dropped Foot Stimulator (ODFS) or the newer PACE. It 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.

Electrical stimulation can sometimes help people to walk faster, with less effort and with more confidence. Stimulators are being continually developed with computer technology allowing them to be more finely controlled and more muscle groups can be stimulated to produce a more natural walking pattern.

What does treatment involve?

You are being invited to attend an assessment session which takes about an hour. The Physiotherapist will take responsibility, along with you, for making the clinical decision as to whether FES is suitable or not and will discuss the reasoning with you. If it is agreed that you are unsuitable for FES then you will be discharged from the FES clinic but will be offered alternative treatment for your walking problems provided this is available/indicated.

If FES can help, during this first appointment you will be loaned an FES box and provided with the other consumable equipment that is required to use it safely. You will be asked to sign a form to confirm that you have been loaned hospital equipment. You will also be given written and verbal instructions on how to use the FES box. A letter will be written to your Consultant Neurologist and copied to your GP informing them of the outcome of the assessment.

How long does treatment continue for?

After the assessment, a further appointment will be made for you to attend the clinic in approximately 6 weeks for review and further instruction. Future appointments are made so that progress can be measured and adjustments made to the stimulator or exercise programme. You will be expected to attend FES Clinic once per year for as long as you continue to use the FES. Some patients use stimulation independently every day, others use it as part of their physiotherapy treatment. Some patients continue to use FES for many years, others only for a period of a few months. Our clinic is set up for those patients who are still able to walk a minimum of approximately 10m with or without mobility aids. If you become unable to walk this distance despite FES use, treatment will be discontinued. Each time you attend FES Clinic a letter will be written to your Consultant Neurologist and copied to your GP.

Are there any risks or side effects from the treatment?

Stimulation causes a tingling “pins and needles” sensation on the skin. Although most people do not find it uncomfortable, a few do and for this reason do not continue with FES. Sometimes, even though patients are carefully assessed, they do not feel that the FES is benefiting their mobility or the treatment has not helped them. Some patients find they are not able to use the stimulator effectively. A few patients have found FES ineffective because they have difficulty positioning the electrodes in the right place. In these cases stimulation will be stopped. Very occasionally patients find that the electrodes irritate their skin. Using hypo-allergenic electrodes (which can be supplied to you if needed) or changing the type of stimulation used (by the Therapists in clinic) can often solve this problem. Very rarely 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 beneficial results. These include an ability to walk faster, with less effort and with more confidence when they use the stimulator. Sometimes muscle tightness (spasticity) is reduced.

Important Information

Please read carefully before attending FES Clinic

If you are supplied with a FES box, this information will be important in helping you to use it safely on a day to day basis. You will also be given a user manual which repeats some of this information. You may wish to bring a relative / friend with you to clinic to help listen to the advice given, if you feel you may require additional support to successfully use FES once at home.

Wearing the electrodes and box

  • The use of the box requires electrodes to be placed appropriately on the skin on the lower leg. These attach into the box via the wire supplied with a red and black end. Usually the black end is attached to the electrode which is highest up the leg but you will be advised about this in clinic.
  • You will be shown where to position the electrodes to obtain the best muscle activity to help your walking. Often people find it useful to mark these positions with a pen initially until they get used to the positions. It may also help to ask someone to take a photograph of the position on your leg as a reminder. You will be advised at review appointments if any adjustments to this are required.
  • You will be given written information to help with this.
  • The switch is placed inside your shoe (attached to a removable insole) and connected to the box via a wire. These wires are usually worn under the trouser leg.
  • The insole with the switch attached can be moved to other footwear.
  • ubigrip is worn over the electrodes on the skin to help hold them in place and prevent the wires from dangling down too low and causing you to trip.
  • The box clips on to your waistband or inside a trouser pocket. Other options of how to wear the box will be discussed if necessary. Replacement equipment.
  • You will be supplied with all the equipment that you will need to get started at the assessment.
  • At subsequent review appointments you will be supplied with replacement electrodes, wires and switches as required.
  • The box runs on a standard 9V battery. You will need to replace this yourself at intervals. You can use rechargeable batteries although these don’t tend to maintain a good output for as long.
  • You will need to replace the insoles and Tubigrip at intervals.

Using the box

  • The settings on the FES box will be altered by the therapist at assessment and at subsequent FES Clinic visits as necessary.
  • Other than any adjustments that you are advised to make day to day, these settings should not be altered between sessions as the box may no longer be safe for you to use.
  • You will be shown how to position your leg (usually in sitting with leg straight out in front of you, with the foot resting over a low stool) and use the test button (red button on ODFS or blue button with white dot on PACE) to test for correct electrode position and how to change this if they are not correctly positioned.
  • The machine has an on/off dial which also adjusts the output – you can alter this yourself, depending on what response you are getting. Often you need to turn it up higher if you are more tired e.g. later in the day or in hot weather or if the battery is losing power (but remember to lower it again when you change the battery).
  • You should use the stimulator for short periods initially and building this up over a week – 10days.
  • Start with 2 - 3 hours the first day, then increase by 1 – 2 hours each day. This allows your skin and muscles to get used to stimulation gradually.
  • Once you have built up to it, you can wear the box all day, switching it on and off as you need to.
  • It tends to be most helpful for those people who put it on as they dress in the am and take it off in the evening but this is individual choice.
  • The box also has a pause button which can be used if you want to stop stimulation for short periods or For example, pause the box just before you sit down as you do not require stimulation in sitting. When you wish to recommence stimulation, stand up and get your balance before starting the box again.(see table below)
  • If you will not be using stimulation for a longer period in the day and also at night, switch it off by the off button to preserve the battery life.

PACE settings (grey box)

ODFS settings (black box)

A long beep is heard when you switch stimulation on and a high pitched beep is heard when you switch to pause.

The on/off button and the pause button ‘beeps’ when you switch stimulation on but is silent when you switch it to off or to pause.


If you leave the PACE box switched on to stimulate but do not use it for more than 10 mins it will ‘sleep’. To wake up the PACE press pause.



If you leave the PACE on for more than 4 hours without stimulating it will turn off. You will then need to switch on and reset the output level.




Electrode care

  • When disconnecting the wires from the electrodes, ensure the box is switched off, then use a twist and pull movement, holding onto the thicker plastic area not the wire itself.
  • Care should be taken when peeling the electrodes off the skin – lift them carefully off by the edges, not by the attached wire as this will break the connection.
  • When you take the electrodes off, put a few drops of water on the sticky side of them, rub this off with your finger. Then apply a few more drops of water and place them sticky side down back on the plastic to keep them moist overnight. Store them in a cupboard or shelf away from heat.
  • You can moisten the electrodes again with water or a lubricating gel e.g. KY Jelly, before applying to skin the next day.
  • You must replace electrodes every 4-6 weeks to reduce any risk of skin infection.
  • You will be supplied with a skin care advice sheet.


  • You may experience a bit of ‘muscle soreness’ in the calf in the first few days – this is a normal response to exercise and will reduce again.
  • Monitor your leg for any increased stiffness / spasms as this can occur but usually eases off again after a few days.
  • Before connecting or disconnecting the wires or touching the electrodes you should always ensure the box is fully switched off. You should ensure your hands are dry.
  • It is very important that you always check your skin under where the electrodes have been when you remove them. It is normal for there to be slight redness for an our or so afterwards but this should gradually disappear. If it lasts longer or there is more irritation/redness/itchiness of the skin you should stop stimulation until this has completely resolved, even if this takes a few days.
  • It helps to reduce any redness in the skin by wiping the area with a damp cloth once you have removed the electrodes.
  • Do not use any skin creams or lotions under the electrode area for a few hours or immediately before stimulating (you can use them elsewhere on your body as normal).
  • Do not shave leg immediately before stimulation – if you wish to - do it the night before to allow the skin to settle down. This applies for waxing also.
  • Some men opt to shave the area where the electrodes sit to make removal of the electrodes more comfortable – the above then applies.
  • Do not stimulate cut or broken skin in the area of the electrodes.
  • Do not drive or operate machinery with the machine switched on.
  • Do not immerse the box in water and remove all wires/electrodes when bathing/showering/swimming.
  • Report and faults with machine to the therapists (try the trouble shooting in the patients manual first).
  • Please be aware of the medical conditions / circumstances detailed on page 1 and should any of these apply to you in the future you must let us know as soon as possible as it may mean you require adjustments to your FES.

Written Information

  • If the FES is suitable for you, you will be supplied with an FES Documents Pack.
  • The FES Documents Pack will include the device user manual, skin care advice sheet, electrode positioning sheet and care sheet, travel letter, precautions sheet, and contact details for the FES Therapists.
  • You will be asked to sign to confirm you have been supplied with an FES box, the FES Information Pack (this pack) and the FES Documents pack.
  • You will be provided with a letter regarding carrying the equipment when you travel, particularly through an airport. When travelling through an airport you should keep all the equipment in your hand luggage along with the letter so that it can be scanned at security. It will not be damaged in any way by doing this.

Further information on FES can be found at 

Or contact your Therapist at:-

MS Specialist Physiotherapists

MS Team Office

2nd Floor

Walton Centre NHS Foundation Trust

Lower Lane


L9 7LJ

0151 556 3742

  • Last Updated:
    01 April 2021
  • Review Date:
    01 April 2024
  • Author:
    J Thain
  • Summary:

    Functional Electrical Stimulation (FES) can help people who have had damage to their brain or spinal cord to move more easily.

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