When you are doing this type of movement:
http://www.junglefitnessoc.com/wp-co...eral-raise.gif
Don't go above horizontal if your palms are facing downward.
I know that's not exactly what you were doing, but it looked close.
TBH I forgot the reason why you're not supposed to go above horizontal but I think it has something to do with shoulder structure and something being pinched or something. Maybe someone else knows.