Symptom Management

Move More Freely with Electrical Stimulation Devices

By Michael Zervas, PT, DPT  and Herb Karpatkin, PT, DSC, MSCS

For persons living with multiple sclerosis, walking and other everyday movements may become a significant problem, limiting independence in the home and community. Persons with MS who have difficulty with movement should see a physical therapist. A PT will examine you to determine your movement limitations, such as walking and balance, and will develop a treatment program to address any deficits. Therapists may prescribe electrical stimulation devices specifically for persons with MS. The purpose of these devices is not to replace exercise and mobility programs, but rather to supplement them in an effort to maximize function and promote greater independence.
There are several different electrical stimulation devices currently available that can be used by persons with MS. It is important to realize that each device has specific uses depending on the individual’s primary complaint, problem, and preference. These include movement-related problems, increased pain, and muscle stiffness, which may make moving uncomfortable or very difficult.
Functional Electrical Stimulation (FES)
FES provides electric currents to certain muscles to allow for assisted movement during specific activities. It is most commonly utilized to treat a condition called “foot drop,” where the individual is unable to lift their ankle upwards, resulting in dragging and/or catching of the foot when walking. Foot drop is very common in MS and can lead to balance loss and falls. Besides treating foot drop, FES can also assist with thigh weakness, and to assist with arm or leg cycling.
FES for foot and thigh
When used for foot drop, FES works by stimulating the nerve that is responsible for lifting up the front of the foot during walking. The device can sense where the individual’s foot is during walking and provide electrical impulses to the nerve at the appropriate time to allow the foot to clear the ground when stepping. Compared to using a regular ankle brace that is frequently utilized for foot drop, FES has the advantage of creating a more symmetrical and normal walking pattern by activating the ankle muscles, rather than merely preventing the foot from dragging. In other words, the FES device allows your ankle to move, while a plastic brace does not. It also has the benefit of being able to be worn in a variety of shoes because of its minimalist design.
FES can also assist with thigh weakness. For those with weakness in the thigh and ankle, Bioness has an FES device for the thigh that works in conjunction with the foot drop component to help control the knee as well as the ankle while walking. It works in a similar manner to FES for foot drop, in that it stimulates specific nerves in either the front or back of the thigh to prevent buckling and allow for greater ease when moving and controlling the leg.
Despite these benefits, FES for foot drop and thigh weakness is not for everyone. If the foot drop is so severe that the ankle cannot be stretched adequately, FES will not be effective because it requires at least some ankle mobility. If there is also significant weakness in the hip and knee muscles, FES for foot drop alone would not be appropriate because it does not control those muscles. In that case however, FES for the thigh and ankle would be a more appropriate option, but there is limited research regarding the effectiveness of the thigh component.

Another potential problem with FES is that the electric stimulation required may be so uncomfortable that some may not want to use it. FES devices also require some sort of training period to find the most appropriate amount of stimulation and where to place the electrodes to optimize its effectiveness.

Lastly, FES devices are generally not covered by insurance, and can cost approximately $5,000 to $6,000. The most commonly used FES devices are the NESS L300 and L300 Plus by Bioness, and WalkAide by Innovative Neurotronics.
FES Cycling
FES cycling has been utilized predominantly for those with spinal cord injury, but can also be used for those with MS. Electrodes are placed on different muscles on one or both arms or legs, and can assist or resist the individual during cycling using a special ergometer (arm/leg cycle). This has a host of benefits, including maintaining available range of motion, strength and endurance training, aerobic fitness, and fatigue and pain reduction. These can positively affect an individual’s mobility and quality of life. An advantage to the FES cycling is that it can be used for all patients with MS, whether they are ambulatory or not. More research into the short- and long-term effects is currently being conducted, but it can be safely utilized in both outpatient clinics and home settings.
Just like with the FES foot drop devices, an FES cycle setup may not be covered by insurance, and can be expensive, about $15,000 to $20,000 for home use. The companies that manufacture FES cycling
include Restorative Therapies and Therapeutic Alliances.

Transcutaneous Electrical Stimulation (TENS)
Transcutaneous electrical stimulation (TENS) is a portable device that provides electrical stimulation directly over the skin to different nerves to aid in providing relief for pain, spasms, and spasticity. They have been utilized for many years for persons with musculoskeletal pain, but research has demonstrated that it is a safe and viable option for certain MS symptoms, especially when combined with other active therapies, such as exercise and stretching.
 Although TENS will not cure the underlying cause of the pain, it may provide some much- needed relief when pain medication is either unavailable or ineffective. Keep in mind,  because there are electric currents passing through the skin, there are some conditions which make the device unsafe to use for
certain individuals. This includes having a pacemaker; being allergic to the electrodes, gel, or tape; having certain dermatological conditions, such as dermatitis or eczema; and use on the front of the neck, or over the trunk, abdomen, or pelvic area during pregnancy. This list is not exhaustive, but should be
confirmed with your PT or MD prior to use.
TENS units are covered by some insurance companies, but are also widely available over the counter from a variety of different companies, generally less than $150.
Physical therapists examine individuals with MS and provide programs that are specifically tailored to the needs of the person to optimize their mobility and independence. Exercise and movement is the most essential component to any program, but electrical stimulation devices can be used in conjunction to help the person achieve their goals and improve their overall quality of life. Electrical stimulation devices are not always to the right approach for everyone, but they could be recommended to you as an option in your care plan if deemed appropriate based on your impairments and goals. Speak with your PT or M.D. to determine if electrical stimulation might be appropriate for you.