There is a kick I have always thought would be very useful if I really needed to injure someone badly or defend my life. But I have never seen it used, or drilled in K.Boxing/M.Thai. My knowledge is limited in this area as I am a boxer, so I'm curious as to what the reason is.
The kick is a stomp at an outward angle right on the knee joint or maybe an inch above. Just imagine crushing right through the knee. If I was to kick someone hard like that, I can't imagine the leg being in one piece afterwards. It's the same concept as a knee bar, just that it snaps. There is no holding it.
The obvious reason I can think of is that if they used it in competition, it could possibly end fighters' careers, which is why they don't use it. But is it in the rules? Is that one of the things your are not allowed to do?
If it is indeed not allowed, then how come it is not drilled with people who do martial arts for self defense purposes instead of competing. It requires little to no skill, and one kick from a small lady like that can seriously injure a much bigger man. Even if she doesn't snap his leg, she will hurt him enough to run to safety.
I'm just curious. I have always thought about this. My natural instinct would be to do this, instead of any other kick. Because one stomp can end it for the guy.