Difficulty moving following a stroke or brain injury is common. One way therapists help people with weak muscles to move better is through electric stimulation.
A healthy muscle contracts when an electrical signal from the brain travels along a nerve to a muscle and stimulates that muscle to move. Therapists can also stimulate muscles to move by using functional electrical stimulation (FES). FES works by electrically stimulating the muscle through an electrode that is placed on the skin.
Functional electrical stimulation (FES) is typically used with other methods of physical, occupational, or speech therapy. The intent is to retrain the affected muscles to move again.
Some new and innovative devices take this concept one step further by combining electrical stimulation with splints, braces or even exercise bicycles. A “neuroprosthesis” utilizes FES to contract specific muscles in a specific sequence. For example, the stimulation could help the hand to reach and grasp, the foot and ankle to step, or the throat to swallow.
RETRAINING THE BRAIN
After a stroke or injury, sometimes the brain and spinal cord can reorganize so that a lost movement is recovered. This is called neural plasticity.
Neural plasticity requires a tremendous amount of practice, and the practice has to be something that is important to the patient. For example, no one is going to passionately lift their hand or foot up or down hundreds of times, but they might work that hard if their practice sessions were for walking or eating.
Therefore, a patient who can repeatedly perform a meaningful task may create new connections in the brain and spinal cord (neural plasticity). The development of a neuroprosthesis for rehabilitation provides the therapist another tool that allows functional recovery of a weak or paralyzed limb.
EXAMPLES OF TECHNOLOGIES USING FES:
The Bioness NESS H200® uses FES to improve hand movements with extraordinary results.
Five surface electrodes integrated into the system stimulate the hand to perform meaningful movements.
VitalStim® Therapy electrically stimulates and retrains swallowing muscles for patients with dysphagia, or difficulty swallowing.
The Bioness NESS L300™ is a small device worn on the lower leg and foot. Through electrical stimulation, NESS L300 helps retrain lower leg muscles, and enables patients to experience a more normal step. The system features a sensor that detects walking patterns allowing patients to automatically adjust to different surfaces, walking speeds and uneven ground.
MidAmerica Rehabilitation Hospital
5701 West 110th Street Overland Park, KS 66211