I have had several instances where my left shoulder seems to dislocate from the socket. This has seemed to be happening more often, and takes very little stress to cause it. The first time I can remember dislocating this shoulder was a few years ago while snowboarding. Ever since my shoulder seems to just pop out of the socket when small forces are applied such as when reaching up to catch a basketball one handed with my arm extended above my head. It is very painful and happens consistently.