Could someone explain what a hammerlock is and why it is significant? Searching just said it's a type of joint lock in wrestling which doesn't make sense to me in this context.
It's interesting, because you have to do something active about it. If you move into hammerlock, you can't continue moving the same way anymore, so you have to decide on some combination of releasing hands, rotating in the other direction, staying and playing in that position, etc.
Then again, I have never danced.