Recently at the gym i've been having this really strange feeling when lifting with my right shoulder/pec, on this particular machine (basically a dumbell fly with the bench to add support) on a weight i find easy, then my pec starts doing like this virbrating thing, and my shoulder joint feels like something is popping out, just wondering if anyone else has had this problem? I've had no serious problems or injuries to my shoulder it just randomly starting occuring one day at the gym and now keeps recurring after about the 9th rep of a 12 rep set.










