I'm not a fan of needles, but it really isn't that bad. It's like acupuncture from what I can tell. You actually don't feel the poke, but you feel it deep down in the muscle. It's kind of weird, but cool all at the same time. Yeah, it's my throwing arm. I had a day in late summer where I played 18 holes of disc golf, then I came home and tried to get our lawn mower running but it was being stubborn. I think that's where I pulled something out of alignment trying to get the mower started.