Neuromuscular Electrical Stimulation (NMES)
Neuromuscular electrical stimulation (NMES) was used to target muscle atrophy due to a prolonged period of box rest following a left hind de-gloving injury. The case presented with atrophy of the left hind; biceps femoris, semimembranosus, semitendinosus and tensor fascia latae had reduced muscle tone, muscle mass and atrophy.
NMES is a muscle preserving therapy which benefits patients unable to exercise. NMES activates the intramuscular nerve branches, via applying electrodes proximally to the muscle motor points. NMES can be used to re-introduce contractions to prevent further atrophy, muscle mass reduction and increase muscular activity. This can be useful for patients who are on box rest or are unable to walk/move like they normally would.
NMES involves type I and II motor units, a voluntary muscular contraction of a muscle involves type I recruitment, then type II. Type II neurons are recruited first during NMES via the activation of muscle fibres through depolarization of motor axons, this is the opposite to the usual recruitment of muscle fibres. Short pulse widths and low/moderate pulse frequencies are recommended, however this causes rapid fatigue due to high stimulation and non-ordered recruitment of motor neurons. The use of wide pulse widths and vibrations of associated tendinous structures during NMES reduces muscular fatigue, enabling longer periods of exercise, increasing strength and stamina.
Molecular changes associated with muscle disuse atrophy can be prevented by NMES, helping to preserve skeletal muscle mass, preventing loss of muscle strength (in less sciencey words, it can help to prevent your animal losing muscle!) Skeletal muscle satellite cells are essential for repair, maintenance and growth of myofibres. NMES can normalise muscle metabolism and re-establish myofibril architecture to its pre-atrophic state. A shift in cytokine profile is created towards anti-inflammatory, contributing to its beneficial effects on muscle loss; it can increase the peripheral blood levels of IL-6 and decrease IL-10 and TNF-a.
Most studies are based on human application with physiological similarities existing worth explored further in the equine and canine patient. Although some of the observed physiological effects are not seen across species, evidence suggests effect on muscle activation is.
For further advice or information how NMES could be used to benefit your animal, please don't hesitate to get in touch. If you are still confused to what NMES is and what it does, get in touch and I'll happily chat it through with you. When people think of a physiotherapist they think of bouncy balls and massage, but we are lucky that in this day and age the use of various electrotherapies can be used and incorporated in to the treatment of our animals to improve their prognosis.