Muscle movement is caused by electrical impulses originating in the brain, which are transmitted via nerve cells to the muscles. When a person wishes to initiate muscle movement the brain sends electrical signals to the muscles. Upon arrival of these signals, the muscles respond by contracting. These electrical signals can be measured over muscles and they are called electromyographic signals: EMG.
and How it Works.
Before brain attack or stroke
If due to brain damage caused by a stroke, regular electrical impulses are not generated
then normal contraction of these muscles normally
controlled becomes impossible.
Although, there are always minuscule “left over” EMG signals, these are mostly extremely small and unable to control the affected muscles. This will often lead to irreversible damage and loss of muscle function thus resulting in paralysis of muscles, like “claw” hand or walking (gait) problems, “drop foot”.
After brain attack / stroke
After a stroke the patient is rehabilitated by physical therapy. Often it includes Functional Electrical Stimulation (FES) or NeuroMuscular Electrical Stimulation (NMES) to avoid as much as possible spasticity of the affected muscles. This is done in the hope that there will be some form of spontaneous recovery and in order that the muscles should not become too stiff meanwhile. In almost all cases spontaneous recovery will not happen however, and the patient is left with severe disuse muscle atrophy and paralyzed muscles, affecting greatly the quality of life.
Devastating paralysis of muscles can often be prevented if the patient is offered the possibility to re-learn to use the affected muscles, by improving the electrical muscle activity. This goal is obtained by combining EMG measurement and NMES muscle stimulation technologies in the Biomove system.
In almost all cases there is still a very small amount of electricity (EMG) left which reaches the muscle. These small “left over” EMG signals are picked up by “stick on” electrodes placed over the paralyzed muscle. The Biomove device then amplifies these small signals and when an internal preset “trigger” level is reached, the built-in electro stimulator returns an electrical stimulation impulse (NMES) to the same muscle. This muscle now responds as originally “instructed” by the patient's own brain signal. This way the patient is able to obtain direct muscle movement, assisted by the Biomove device.
After stroke with EMG triggered NMES
The patient uses this method of cognitive re-learning to rehabilitate the muscles of the otherwise paralyzed hand or foot. By using this advanced form of biofeedback the central nerve system learns which part of the brain to activate. By training at home with the Biomove EMG triggered NMES device, important improvement of the overall electrical activity of the paralyzed muscles is obtained, originating from the brain itself. This leads towards regaining significant muscle control by the patient.
The combination of EMG and electrical muscle stimulation (EMG controlled NMES) enables the patient to take full advantage of even the tiniest electrical activity left after a cerebrovascular accident (CVA) or stroke, contributing significantly towards successful rehabilitation.