i was doing incline DB presses tonight and on my last two reps of my third set, my left shoulder popped- it has done this before, too. so when i got to doing my cable side laterals, it just killed my left shoulder. this, like i said, has happened in the past. the first time was when i was doing upright rows several months ago, and it did the popping thing and hurt for like a week afterwards. what can i do to prevent this from happening? i was able to switch to DB lateral raises as a substitute and it didnt hurt much.......