Electric stimulation can be muscular, general and transcutaneous electrical nerve stimulation (tens). the muscular type of electric stimulation seeks to strengthen the muscles by reducing muscle spasms. also known as ems, this stimulates the skeletal muscle using electric impulses to cause muscle contraction. while an ems device may be able to temporarily strengthen, tone or firm a muscle, no ems devices have been cleared at this time for weight loss, girth reduction, or for obtaining "rock hard" abs.