Electrical Muscle Stimulation (EMS) E.M.S. stands for Electrical Muscle Stimulation. EMS is predominately used by doctors and physical therapists to prevent, or reduce, muscle atrophy. Atrophy is the weakening and loss of muscle tone, may be experienced after surgeries or injuries. EMS has proven to be an effective means of preventing muscle atrophy. Doctors also see EMS as a means of increasing blood flow to muscles, increasing range of motion, increasing muscle strength, as well as enhancing muscle endurance. Our muscle stimulator is used to treat muscle related pain, such as a spastic muscle, sore muscles, or tight muscles.