I'm currently doing some research and actually they're now saying that normal TENS machines deliver way too much current which does block the pain, but does nothing to help tissue heal. Microcurent machines (MENS) are being touted as delivering the kind of current that you don't even feel but is in line with the bodies natural current. Supposedly damaged tissue becomes positively charged and introducing too large of a current will cause it to bypass the damaged tissue altogether. The microcurrents......5MA or less......are able to penetrate the cell walls. This has just been by reading so far.....anybody else heard of this?