Theoretically monophasic microcurrent indeed can cause skin burns. However, I never observed this. I can't count the times I used it and many patients had conditions (including diabetes) leaving their skin in bad shape. If still in doubt, the solution is simple, use the biphasic microcurrent pulse. Many manufacturers of microcurrent machines have these biphasic pulses as well, some even only have these. I worked with a wide variety of microcurrent devices and observed equally good results with the biphasic pulses.
Patrick De Bock