Electrical muscle stimulation (EMS) stimulates the muscles using electric currents so they contract without the client actively participating. This treatment is often used in physical therapy when someone is recovering from an injury, but many studies have explored whether it is useful in other applications.
How It Works
Electrical muscle stimulation, sometimes called EStim, is non-invasive and non-pharmocological. It affects many parts of the muscle cells, including ion channels, proteins, and organelles, and causes a variety of interactions that alter the activity of the cells.In other words, EMS mimics the signals that come from the central nervous system, causing muscle contraction. This repetitive contraction increases blood flow, improves strength, and slows muscle loss.
Critically Ill Patients
A major complication for critically ill patients is an increased loss of muscle mass, which is attributed not only to the illness but the immobilization necessary for patients in an intensive care unit (ICU). One study examined the effects of using electrical muscle stimulation on ICU patients to slow muscle loss. The results showed that EMS during the first week of admission to an ICU preserved a large amount of muscle mass. Plus, the patients who received EMS saw benefits even in muscle groups that were not directly stimulated.
Electrical muscle stimulation has also been studied in people with chronic illnesses, including chronic heart failure and COPD. People with these conditions cannot actively exercise due to their heart and lung insufficiency, and EMS therapy proved beneficial for improving muscle performance and quality of life.Participants saw improvements in endurance and structural changes in the muscle.
Electrical muscle stimulation is not without complications. One study showed that EMS caused significantly more injuries than physical exercise.In addition to causing contractions, it also desensitizes some neurons and may stimulate other structures in the tissues and vessels. Muscle injury may occur, and there can be skin irritation where the electrodes connect to the body.
Whole-body electrical muscle stimulation is often touted as a viable alternative to physical training. Some fitness centers offer it, and personal devices are available. However, the effectiveness of whole-body electrical muscle stimulation is questionable.Evidence is lacking that it is any more effective than conventional training to increase muscle mass or force.
Whole Body EMS and Sarcopenic Obesity
Sarcopenia is a loss of skeletal muscle mass and function. It is common with aging or after long periods of immobility.Electrical muscle stimulation has been studied as a possible treatment for elderly patients with sarcopenia and obesity. The results of the study were inconclusive, and some people in the trial reported discomfort during the treatment and muscle soreness after.
Whole Body EMS and Heart Failure
Whole-body electrical muscle stimulation has also been studied in patients with heart failure. People with heart failure benefit from regular aerobic exercise, and whole-body EMS was explored as an alternative to physical exercise. One study showed that extended whole-body electrical muscle stimulation could improve oxygen uptake and heart function in this population.
Whole-Body EMS and Cancer
One pilot study investigated the use of whole-body electrical muscle stimulation as an effective exercise technique for advanced cancer patients receiving treatment.The results show that whole-body EMS combined with proper nutritional support has positive effects on muscle function, though further studies are needed to reveal the full effects and whether there is any impact on disease progression and survival.
Though relatively uncommon, rhabdomyolysis is a life-threatening complication of whole-body electric muscle stimulation. The condition is caused by muscle breakdown and can result from over-exertion.In rhabdomyolysis, muscle cells break down, releasing protein into the blood. The kidneys remove this protein, but too much of it can damage the organs, leading to kidney failure.
Studies on electrical muscle stimulation are somewhat limited, and minimal contraindications have been identified. Patients with pacemakers have been eliminated from some studies. Pacemakers contain a pulse generator with a battery and electric circuitry and electrodes that deliver electrical pulses to the heart, and the EMS electrical signals can interfere with the devices.