EMTs disarm people all the time. I've seen it done. Between keeping your side to them, sweeping them if you're down, and if they're girls, hit them if they get you with an underhand. You can absolutely disarm your average woman if you are a man in decent shape. I don't really want to fight a strong guy of my own size, but I guess I am not really worried about some random woman who probably buys her vegetables chopped at Whole Foods from stabbing me. In my limited experience, most women with a weapon don't really want to fight.