--that I use on all sorts of body parts, just so that I can get some relief from all the wonderful parastheses that kick up.

TENS is not healing in any real sense--on needs higher intensity IFC for that (which physical therapists or chiropractors often have), but it does help to replace annoying sensations with another sensation that is regular and one can get used to. Pain signals, in particular, are, oddly, the slowest transmitted signals through nerve pathways, and TENS vibrations/pulses are transmitted more quickly and interfere with those sensations.

I have to say with mine, it's nice while it's on, but there's no continued after-effect--as soon as I shut it down/take it off, the parastheses seem to come back.