Versatile FES Technology for
Walking with Confidence
Improving Walking Ability
in Children Adults with
a Neurological Disability
Clinical Excellence & Expertise in
providing Functional Electrical
Electrical stimulation is used to improve muscle strength in conditions where there is weakness of muscle as, for instance, after knee surgery.
Because a dropped foot stimulator activates muscle during walking, continued use may improve the functioning of a weakened (paretic) muscle. However, a more important effect may be improved overall conditioning due to increased periods of walking because the stimulator makes walking easier.
Walking with an ODFS after stroke or MS may lead to increased activity/ endurance (less time spent sitting) and improved physical conditioning.
The stimulation feels like a mild or moderate tingling in the area where the electrodes are located.
Because the stimulation is triggered by the heel switch, this tingling sensation comes on when the heel is lifted from the ground and ceases when weight is taken on the limb.
Movement is also felt at the hip, knee and ankle. The majority of people fitted with the device find the sensation from the stimulation comfortable. The sensation generated by the stimulation also “cues” the gait pattern in that it provides feedback to the user during walking which sometimes can be helpful.
You will need an initial assessment as described above. Following this, if you wish to be fitted with a device, a fitting appointment is necessary. This takes 1.5 to 2 hours.
A follow up appointment is scheduled within a week of fitting as it may be necessary to adjust the stimulation pattern slightly. Follow up is also important so that you, the user of the device, can give feedback to the clinician who can adjust the stimulation as necessary to improve the overall effect, provide education on use of the device, monitor your progress and answer any questions you may have.
Following this, a 2nd follow- up should be scheduled at 1 to 3 months to re-evaluate your gait with stimulation, make any minor adjustments to the settings and check the usage log on the stimulator to provide you and your clinician with feedback on how the device is being used.
The reported benefits from studies of the ODFS include improved walking speed and endurance, less trips and falls as the foot doesn’t catch on the ground, greater walking confidence and increased range of walking.
An initial improvement of 20% improved walking speed has been reported in clinical studies of stroke and MS patients who used the ODFS. This improvement, known as an “orthotic effect” is because the stimulator bestows an immediate walking improvement by lessening the drag of the foot on the ground and provides assistance with swinging the leg.
An ongoing improvement of approximately 27% improved speed can be expected with continued use of the ODFS. Measured reduction in effort of walking with the ODFS averages 36% in MS patients.
The ODFS is a walking orthosis and has been covered by some Extended Health providers according to the individual coverage of the particular plan. However, coverage varies across different providers and provinces.
Your clinician and family physician can provide the necessary medical prescription and documentation that you will need to apply for re-imbursement after you have been fitted with a stimulator.
An ODFS costs a little more than a custom made brace. With assessment fitting and follow-up, the overall cost is in the region of $2,100.
Electrodes are an on going cost associated with use of a stimulator. Monthly cost for electrodes averages $16.
An assessment by a clinician trained in fitting the ODFS is necessary to determine its suitability in your particular situation.
The assessment involves a physical evaluation of your strength, balance, present gait pattern and walking function. The ODFS is then set up for you to walk with stimulation so that you and the clinician can compare your walking pattern with and without the device.
You can determine its potential benefit to you. If you feel your walking is improved with use of the ODFS your clinician will assist you with ordering a device.
The ODFS works by stimulating a nerve in the leg (the common peroneal nerve) to assist with lifting the leg in a stepping motion (swing phase of walking).
The stimulation is triggered by a switch placed under the heel . Every time weight is taken off the heel the stimulation comes on and stays on until the foot contacts the ground again.
The ODFS can also help to stabilize the foot and ankle on initial weight bearing (stance phase of walking) thus assisting balance and safety while walking.
There are no documented adverse side effects from use of a dropped foot stimulator. However, certain habits need to be established when using a device. These include daily cleaning/refreshing of electrodes after use and disposing of used electrodes when they deteriorate with use.
Not observing these practices can lead to skin irritation over the electrode sites and the possibility of not being able to use stimulation until the irritation is resolved. Your clinician will provide the necessary education around proper use of the device and it is important that you follow the protocols outlined.
Yes, even people who rely on wheeled mobility can benefit from the exercise and increased activity level that a dropped foot stimulator can provide.
A recently published research paper* has highlighted the value of physical activity and exercise as a means of maintaining function and promoting positive health benefits in MS. The authors, in summarizing various studies, report “the consensus from research conducted to date supports the idea that there are many benefits associated with regular physical activity or exercise training in MS. In individuals with MS the fitness benefits of exercise, such as improved cardiovascular function and increased muscular strength, are comparable to those seen in individuals without MS”.
* Vollmer TL, Benedict R, Bennet S, Motl RW, White AT, Bombardier CH, Hebert JR. Exercise as Prescriptive Therapy in Multiple Sclerosis: A Consensus Conference White Paper. International Journal of MScare; Vol 14, Supplement 3, June 2012.
It is also recognized that finding the right activity and adhering to an exercise program can be a challenge in MS just as it is for the general population!
A dropped foot stimulator can play an important part in overcoming the difficulties associated with physical inactivity in MS. Simply by making it easier, a stimulator can facilitate walking and enable cardiovascular exercise. Even people with more advanced MS who rely on wheeled mobility can avail of the technology and use a dropped foot stimulator for exercise walking, gaining physiological and psychological benefit. It allows enjoyment of an everyday activity that might otherwise be difficult or impossible.
In summary, a dropped foot stimulator allows a “take charge” approach to exercise, mobility and an activity program best suited to the individual’s needs.
Odstock technology can help in any or all of the following situations:
1. When there is muscle weakness in one or both legs – weakness at the ankle makes lifting the foot difficult – the foot drops and drags on the ground. Additionally, hip weakness makes the leg feel heavy and difficult to move. Walking is fatiguing due to the high energy demands of moving the legs. Walking is also slow and there is a possibility of falling due to leg weakness and catching the foot on the ground while walking.
With these symptoms, an Odstock dropped foot stimulator can help — by stimulating the common peroneal nerve in the leg, the foot lifts during stepping and foot drop is corrected.
Hip weakness can also be addressed – by varying the position of the stimulating electrodes it is possible to induce movement concurrently at the hip, knee and ankle which helps to lift and move the leg forward overcoming weakness at the hip, knee and ankle. The overall benefits that one can expect include improved walking speed and increased walking safety due to a more efficient gait pattern.
Range of walking (distance) can also be increased because there is less muscle fatigue. If weakness affects only one leg (unilateral weakness) a single channel stimulator may only be required. If weakness affects both legs (bilateral weakness) a 2 channel dropped foot stimulator is generally best.
2. When there are leg spasms or spasticity (increased muscle tone in one or both legs). The leg muscles feel stiff, resulting in limited walking. It is difficult to bend the hip, knee and ankle to take an adequate step. Walking feels inefficient even though the muscles in the legs may be quite strong and there is no obvious foot drop.
With this physical presentation, a dropped foot stimulator can help – Stimulation reduces the “extensor” tone (tightness that makes it hard to bend the leg) and makes lifting the legs and taking steps easier. Benefits include improvement in walking speed and ability to walk longer distances. A 2 channel stimulator is often prescribed as the extensor spasticity generally affects both legs.
3. When there is ataxia (decreased walking co-ordination ) and co-ordination of the muscles responsible for walking is difficult. The normal “heel-toe” gait pattern is difficult to maintain. Walking any distance is difficult. The ataxia in particular affects outdoor walking and makes it hard to maintain a normal level of activity such as going to the mall or to outdoor events.
While FES does not address the cause and symptoms of ataxia directly, nevertheless, a dropped foot stimulator provides benefit that can reduce the effect of the ataxia. Stimulation of the ankle muscles as the foot is lifted “pre-positions” the foot for stepping and bearing weight. Restoring the normal heel-toe pattern and improving the trajectory of the foot during walking makes the overall walking pattern more efficient and can reduce fatigue associated with decreased co-ordination. Correcting the heel- toe gait pattern with a stimulator on one side can have an overall beneficial effect on walking.
4. When overall walking endurance is reduced and outdoor walking especially is difficult: Although the leg muscles may show close to normal strength and physical endurance is relatively good, walking over longer distances is a challenge. Foot- drop develops with distance walked. Consequently it becomes necessary to limit walking to what can be managed before fatigue and foot drag become a problem.
A dropped foot stimulator can be worn for outdoor walking to lessen the effect of dropped foot that develops with fatigue. The stimulator can be turned on when needed. Stimulation improves foot lift and the overall gait pattern, making it easier to manage outdoor terrain – inclines, grass, gravel, curbs and concrete. Wearing a stimulator for outdoor walking can increase the user’s walking range and allow a more normal daily routine for shopping needs and recreational walks. It may help to preserve a more active lifestyle and reduce anxiety associated with outdoor mobility.