Regarding the force that pushes the carrier waves, the operator must determine the Intensity (µA) that is appropriate for the patient and the particular area where the probes are being placed. For torso and legs, we can use up to 600 µA; for the head, neck, and face, we use no higher than 200 µA.  Unlike the large structures of the torso and extremities, the head requires less of a push because it is more densely packed with nerve tissue and has more delicate, superficial connective tissue. Low Intensity, a gentle push, is often all it takes to reestablish increased cellular activity levels.

In any case, if any electrical sensation is perceived, we lower the Intensity to sub-perception threshold.

Probes and electrodes also vary the requirement.  The smaller the electrode skin contact surface, the more focused and concentrated the current; i.e., the Narrow Tip or Auricular Probe is more likely to produce electrical stinging because it is funneling all the current into a tiny entrance.  Whereas, the Mini Plates, Large Plates, Roller Electrodes disperse the current, spreading it out across a broad surface which offers less resistance. Thus, we generally use lower Intensity when using Tips, especially on the head, neck and face.