Originally Posted by Bluetick
Just get up and leave the room. Refuse to be held hostage by a child. If she passes out just leave her, don't try to catch her. A couple of bumps and she will learn it hurts and she will start to lay herself down.
Something along these lines. She's doing it now because she enjoys the reaction/attention she gets from it. Sometimes the hardest thing as a parent is not reacting the way the child desires when they do stuff like this. You either train them, or they train you -- but ultimately it is your decision.