The techniques we train to deal with knife attacks consider that a cut or stab to a limb is not as bad as a cut or stab to the vital organs and structures in the abdomen, neck and head.
We know we are likely to get cut. We are training to mitigate that to the best of our ability.
Of course we are looking to cause grave injury to the attacker: that is part of EVERY technique. NONE of our techniques "grab the knife hand" and STOP.
(What do you think we are doing while controlling the knife hand?) But in doing so we are also looking to ensure we are not taking multiple wounds to vital systems.
Just to make sure we understand each other, lets deal with a concrete example:
One of our techniques presupposes the attacker stabs downward with an icepick grip (we have other techniques for other angles of attack; lets just stick with this one for the moment) with a right hand.
Stepping in to meet the attack, our left arm strikes in an upward rising block-type motion; right arm slips behind their elbow; driving them to the ground with, if they haven't already hit the ground, a major outer reap to the attacker's right leg.
As the attacker hits ground, we grab knife, dislocate shoulder (or vice verse: dislocate shoulder to encourage them to drop the knife ...)
We will probably get cut on our left arm. Few people will hit the ground head first backward without significant injury.
Suggest how better to "shut off the head" directly while ignoring the knife if facing this specific attack
This is actually a good example of a standard defense against a knife. It is one that my father taught me. But, there is a problem with it. So let's step back just for a moment, and think about the three kinds of basic fighters there are in the world. Offensive fighters, defensive fighters, and counter fighters right? I mean that's a pretty simple concept. Now, you can pretty much throw the counter fighter out of the picture because he is still defending to mount an immediate attack, or offense. So we now have two kinds of basic fighters offensive and defensive. The reality is we can't do both at the same time. Your either attacking or defending, no matter how you look at it.
So your basic ice pick downward strike with a knife is a great example because whether you are going to hold on to the knife or throw the knife you still have to have some kind of aim to hit your target. The same is true with guns, knive, knees, punches, kicks, elbows, knees, etc...they all require aiming. Putting your strike where you want it. A moving target is obviously harder to hit than a stationary target right? So your gonna say, "Yeah exactly!", but here is the caveat to that, a target 5 feet away that bursts at you with everything it's got, is no longer where your aim was at. They've moved. So let's look at what we can take away from your basic technique.
First we have an opponent striking with a downward strike. So we are going to either step back or step forward into our neutral bow, while executing an upward strike or block with our left arm to his right downward knife weilding travelling arm. At the same time we are going to grab his elbow, (Which we didn't break yet, nor did we break the knife arm, we've merely stopped the attack momentarily), and sweep his legs out from under him, hoping he'll drop the knife, and we'll get a dislocation.
On the other hand, when he attacks with that knife in his downward arc, we could just burst forward with our forearm in the lead, putting all of our weight behind that one strike and strike him in the throat. Now, if we're slightly late we may get struck on the left shoulder, but because we've moved inside of the knife's arc we probably won't get stabbed. We might get a two fer on this one. He might hyper extend his elbow if were late and he lands just right on our shoulder. Don't count on it, but it could happen. We know were going to crush the guys throat, even if we don't we know he's going to move backward, drop the knife and grab his throat. If he doesn't drop the knife he's going to cut his own throat, and from there we just start piling on injuries. I just bypassed three whole steps in your technique with one and got a result that is going to allow me to get more injuries and results. Plus I didn't have to mess with the knife, at all. I just hit the guy and got a result.
Now, wait a minute right, that's all well and good if your standing but what if they have you on your knees. The same applies, just the targets are different. Now you would burst forward with your weight, into the guys testicles causing him to bend over, or his bladder even, it's going to make him bend over. Or you can throw your weight behind a left to right or right to left strike to the knee either one is fine, and buckle or perhaps even dislocate or break it, the one that has the most weight on it, is preferable to make these knee strikes work. But either way, you need to get him to stop attacking and starting defending, or trying to anyways. Once his knee buckles and he falls, then it's just a simple matter of striking the first target that you see, which is probably going to be the testicles, punch him in the gonads dude. He's going to bend forward to protect them after the fact, he just exposed at least 2 more targets, from there, break a clavicle, or strike the carotid artery, or for a third grab his head and begin to gouge his eye out. Remember this guy pulled this knife on you not because he wanted to ask your sister out on a date, but because he wants to kill you.
If you don't like going for the knees as he steps forward with his left foot, drop your weight with your forearm leading just above that little knob on the ankle and break it. Very effective.
YOu see the difference in thinking? I'm not the one having violence done to them trying to play catchup with defense. I'm now the one doing the violence, and that is what you want. If your having to try and stop the violence using socially acceptable rules, you may get hurt very badly. You play by their rules, (The bad guys), and you flip the tables on them, and just start doing the violence. Once you get an injury everything changes in your favor. The secret is in striking targets, but not just targets, destroying those targets so that they don't work anymore. When your done with this guy there should be life altering changes done to his anatomy. Whether it be that he limps for the rest of his life, only has one eye, or is dead. Something should be destroyed. It's not pretty and nobody likes it, and nobody wants to do it, except the guy doing it to you. He loves it, cause he's getting what he wants. What does he want? YOur life. For him it's just another day at the office. The same way the lion hunts it's meal and kills it for food. It isn't bothered by the fact that it took a life, it's just how the lion survives. THe same with these a-social sociopaths, it's just how they live, and if your in the wrong place at the wrong time, they are going to do everything in there power to do you in. If respond with anything less than utter violence, you play russian roulette with your life.