This so simple, and yet the first day I wore it at work all day, I didn't get the same level of pain I usually get at all using the mouse!! If there was any pain in my arm, I just adjusted to position the pad over the muscle in line with the discomfort, and problem solved. Actually, having worn it every day at work for a few weeks, I find I'm forgetting to use it as much because I don't get the pain unless I'm doing a particularlly repetative task on CAD. I've had years of tennis elbow and golfers elbow because of using the mouse, and used numerous devices to try to help, and then I buy this little thing, and it's suddenly so much better. Very pleased with this!