them? if not they stay where they are till professional help arrives. if the person is unconscious or in pain - especially when they try and move themselves, then they stay where they are for sure. you may need help to keep them there sometimes.
the reason for this is they may have a spine injury and you could easily make it a lot worse by moving them.
make them comfortable and get help.
the exception of course is if you have to get them away from some danger such as fire or a live wire, then be very careful how you move them. 