I move around a lot while asleep?

and I think I may have some sort of sleep disorder? I move around a lot while I'm asleep, shifting, kicking-I know I punched my sister while I was asleep once. I also have bruximsm-that is to say, I grind my teeth at night-but I don't know if that's related or not. Basically, I annoy the crap out of anyone who shares a room with me, let alone a bed. I think that somehow the paralysis that people are supposed to enter into when they reach the REM stage-the one that's supposed to keep you form living out your dreams-has somehow been disrupted. Although I have never sleepwalked or anything like that, as far as I know. Is there anything I can do to stop this happening? It's kinda embarrassing whenever I sleep over at a friend's house...but, being asleep and therefore unconscious, I can't really control my actions. What should I do?