I've done these a year, may have helped: http://stronglifts.com/shoulders-dislocations/ Watch a few vids on Youtube on how to overhead squat. You have to pinch your shoulders back, take a very wide grip, and understand that the bar must be held BEHIND your head, not over your head. I tried them a couple times throughout the last year and only this third recent attempt did it work out. Oh, by the way, I can't do a full squat with my hands in the air, either. I need the bar to apply pressure between my arms and keep my arms behind my head.