a tens machine blocks pain signals via electrical impulses. i have a chronic muscle spasm in my back, its literally one band of muscle, its very annoying (i have a t8-t9 disc bulge) but this muscle spasm is literally the only pain i have, i dont think i have any disc pain at all. i've just started trying a TENS machine it seems to really help. given that my muscle is in spasm, im assuming this is the spasm-pain-spasm cycle at work, if i persistently use a TENS unit several times a day is it possible to break the cycle and eventually take my muscle totally out of spasm? by taking away the pain part of the cycle, the cycle will stop?