Re: shoulder injury
I have recently recovered from an A-C injury (i.e separated shoulder), several people here have recommended seeing a specialist, and I agree. This injury can linger and recur if you aren't careful with it. That's what happened to me, I tried to go back to class a few days afterwards and I think that I pushed it too far.
As strange as it sounds, my chiropractor (who is a martial artist), was able to help me.