Aaww dude, sorry to hear that. I assume you're a bodybuilder. Most guys wreck their shoulders doing all those "behind-the-neck" exercises. Claims that those exercises are better are simply unsubstantiated. I injured my shoulder around 18 months ago. It subluxed frequently and no amount of rehab helped. I also was diagnosed with impingement syndrome. I bought this book called "Trigger Point Therapy" by Claire Davies. You may want to look it up on Amazon. I've resolved all shoulder problems, thanks to that book. The shoulder is a very complex joint. You should exercise a lot of caution both while training and during rehab.