Hey guys, I'm just a casual boxer I guess (me and a couple of buddies bought some gloves a couple of months ago and get together everynow and then...)
I have a little problem with my shoulders and always have. They pop out at random times, most recently when trying to throw a right hook. When this happens I have to stop while I struggle to put it back in which usually takes a couple of minutes. Following this it hurts and aches and I can't box anymore that night.
Is there anything I can do, some sort of strengthening, to at least minimize these occurrences?

P.S. It happens with both shoulders.