Say you have an average-sized woman facing off against a guy who's at least 6 feet tall and built like a tank. She manages to kick him in the back. Assuming that this fight is taking place on earth and not in the Matrix or anything like that, what happens?
1. It doesn't seem to affect him at all.
2. He falls forward.
3. He falls on his back and his sword launches itself into the chest of some innocent bystander.
I think you can guess what teh winnar is here. Sure, every writer has to start somewhere, but I can't help but snerk at such a blatant violation of the laws of physics, especially because the first thing it brought to mind was Mortal Kombat: Annihilation with its fight scenes full of people randomly flying in all directions.