Some time ago my shoulder did something odd while climbing. In an awkward position on a crack it seemed to lever out of joint, almost as if it was partially dislocating. At the time it was very painful, but after a weak or so of soreness it cleared up. Recently it's happened again on two occasions, the culprit seems to be awkward cracks where I force it to go through a range of motion it obviously doesn't want to. Mid route, it's rather disconcerting and although when it happened today it wasn't particularly painful it did put an end to climbing so I'd like to stop it happening if I can.
I'm sure my best bet is to go to a physio, in the meantime I always hear the phrase 'shoulder instability' being bandied about and various exercises suggested as means of remedying it. Is this semi-dislocation/weird poppy outy thing the same thing as 'shoulder instability'?