If you arm was in a cast and you couldn't use your arm then this will help your arm from atrophy. But if you can train then this is just another way to throw your money away. Does it stimulate the muscle, yes. Will it make you stronger, no. Will you notice this machine while lifting weights............no way hosay.
The Germans were using a muscle stimulation machine that was turned up so much it would pull the muscle right off the bone. Do they use it now, no. This machine might work for you if you are bed ridden and want to keep the muscle tone. There is no such thing as spot reduction. If you slap all 10 pads on the abs you will still have the same amount of fat on your stomach as before.