Electrical Muscle Stimulation (EMS) is a way of contracting a particular mucles in the body. For this purpose, a small Electrical device is used and electrodes are attached to the body. One can adjust the power of electrical stimulation using that device. Ususally low power is applied to smaller muscle groups.
EMS has mainly three benefits which are training, recovery and rehabilitation. Since EMS can provide greater contradiction compared to it helps you train in a more efficient way. We should also note that EMS bypassess stimuli transfer through central nervous system.
According to U.S. Food and Drug Administration there are two major categories for EMS: over the counter devices and prescription devices.