Is this normal for my arms to do this?

okay.. this is a little video of what my arms can do since i didn't know how to describe it. My doctor said he's never saw it before?? So uhmm, tell me what you think about this??? I can't play sports because I'm afraid it will be EASILY dislocated? ?? a href="http://www.youtube.com/watch?v=oLuCCV-t3fA" rel="nofollow"http://www.youtube.com/watch?v=oLuCCV-t3…/a