WHAT IS BIPHASIC AND MONOPHASIC?
With the Biphasic waveform,the current travels in both directions and as a result, allows for even distribution of electrical stimulation from both pads, allowing symmetrical development of the muscle. With the Monophasic waveform, the current only travels in one direction, the power on each pad is not as evenly distributed as in a Biphasic machine. (ie.. one pad is appears to be weaker), so it is necessary to pair the pads from each channel on one muscle group.