[yy]

this is actually a spin off of disarming robbers.

How deep would a knife have to cut the forearm to prevent a trigger pull?


seems to me if my knife is at the ready (and concealed by my body), then I should modify the pistol disarm. Afterall, I'm stepping off axis, parying the gun hand, and have my knife hand full.

I am not looking for "this many fractions of an inch", but rather "human anatomy prevents such a cut to stop a trigger pull effectively." Which is it?

[JShirley]

I think attempting to use a knife to stop a trigger pull is essentially pointless- at least, by attacking the arm.

A better idea would be to get offline and go for a vital spot, while remaining in a posture that prevents being engaged with assailant's firearm. You are, after all, in mortal danger.

John

[hso]

yy,

I'm gonna agree with John and add that depending upon the knife to cut enough tendons and ligaments to stop a trigger from being pulled is a vanishingly small chance. There are just so many practical problems that I wouldn't bet your life on it, much less mine. Angle of attack, clothing, movement, the list goes on. Your best bet is to incorporate attacking the arm with the knife so that it is pushed off line by the cut as you get off line in the other direction. This means that you're setting up for the follow through, which is going to be a thrust or cut to the vitals (throat) while you control the gun arm to keep it from coming back in line with you.

[Skofnung]

I'm with Mr. Shirley on this.

I'm just a beginner at knife fighting (I've been taking Arnis for several months now) but from my experiences with unarmed fighting, don't try to get fancy when it is for real.

[Wasz]

In my readings yeah im gonna say dont worry about it and just dont do it. However feel your wrist and flex your fingers when you do it. Those are the tendons that allow you to open and close your hand. If you cut deep enough to sever them, then it should translate to in ability to pull the trigger. You have to cut deep enough and cut them all lest you miss the trigger finger tendon, and the round still goes off. I have no clue what to do exactly but with a knife even a deadly cut or stab can take some time to finish an enemy. So possibly with a cut of this nature and thusly disarming the enemy you may be better off. But I dont study knife fighting and that is simply something that just crossed my mind.

[MadMercS55]

You could stop the trigger pull if you chopped off the BG's hand! :D
It really wouldn't be wise to rely on trying to stop the trigger pull. It would be better to try and disable the attacker's arm by inflicting massive damage, or perhaps trapping the arm and going for a kill\lethal zone.
If you already have your knife deployed, stay off center, attack or trap his weapon arm and flow from there. If he does not have the firearm fully deployed, perhaps trapping his arm and cutting other vitals before he fully deploys his gun. All depends on distance, reaction vs action, etc etc. The possibilities are endless in such instances, either way, relying on cutting of tendons to stop a trigger pull could be costly in the end.

[yy]

That was cool.


I was staring at my forearm for a long time and suspected that too many variables exist. I just couldn't envision a line of cut/thrust that would be effective. Even a cut to the bone can still leave some tendons intact.

Mr. Shirley articulated my suspicion much better than I. It's good to have confirmation. I just had a feeling that an inner-arm cut would be enough to make the knife hand useless, but not enough to prevent a light trigger pull. the same goes for the nerve on the top of the forearm.

hso: you read my mind. I visualized exactly that my knife would come inline as I step off line. But what to do about the gun? It may still be in the robbers hand even if I've weakened the grip.

[hso]

MOVE

and keep moving


The cut is an upward slashing cut or a hacking downward cut, but in either case it incorporates a pushing away motion. The free hand can trap at the wrist to pull the gun hand off line. The knife must keep moving. You never stop it's movement. If cutting up and pushing away the knife cuts or thrusts to the throat or armpit while the gun hand is held off line. If hacking down the free hand holds the gun off line and the knife then moves to a bladder stab.

[JShirley]

Did I just gain 20 years or something? :scrutiny: Mr. Shirley was my father.

Here's something else to consider: if you have the chance, try to control adversary's limbs without actually grabbing them. Something about encircling your attacker's limbs with a hand makes them automatically resist. Cover and control, but don't grab if you can do what you want without it.

One technique I like is omote gyuaku. If the uke has a handgun in a classic squared off hip-level "gunfighter" posture, and extends the handgun towards you, drift to his outside. Let your left hand lightly touch/cover his gun hand (assuming he's r handed). Extend him out slightly, as you bring your r hand up to grab the underside of his gun hand.

You should be parallel with his gun arm, but very close. Then, rotate his gun hand back towards him (and away from you), as you pivot 180'. You will cover him with the muzzle, break his wrist, and most likely, his trigger finger. If you continue moving after your body pivot, you can take him down to the ground. This same technique can be used with a knife, but exercise caution!!!! A swift and aware attacker can open you up if you're not careful.

Now, I know this is not inherently a weapons-wielding kata, but defensive tools just give more options. ;)

With the same basic setup, with a drawn knife, after getting outside, you might perhaps cover his gun hand by lightly touching his thumb with your blade. You should only try this if you're confident and feeling merciful...don't think I would. I think I'd be more inclined to get outside, jam my knife upwards into his armpit or bottom of his weapons arm tricep, and

RUN.


Just John

[hso]

John, your omote gyuaku is similar to a technique we practice. We vary by shuffling to the left and forward and reaching with the left hand in a "tiger mouth" (thumb and finger forming a "U") to the forearm. We slide the hand down the gun/knife arm until the wrist of the gun hand acts as a stop and we apply slight pressure in the direction the gun is pointing to upset the balance. The opponent will almost always pull back against the pressure instinctively. At this time we mimic your technique and using the right hand meet our left in a basketing grip around their gun hand and "help" them pull their arm back but turn their hand and gun towards their midline and up under their chin. We depart again from your technique by then shoving the gun up into their throat as a strike. With luck it goes off and blows the back of their head off. If not we then continue to your technique and continue to turn the hand breaking the wrist and arm.

If this were a knife the technique keeps our hand off of the blade and thrusting up into the throat has obvious benefits.:evil:

[Freddymac]

I boiled a lot of DR. mombo-jumbo and latin into this:
she said that what would matter was not how deep the cut was. What would matter, would be severing the ligiment in the forarm that controls the ultimate movement of the finger. If you move your finger and push just above the wrist, you can feel it. Depending on how far up the arm that you go, that would determine the depth of the cut needed.

Fred

[tellner]

The disadvantage of guns, particularly at close range, is that they don't do much except make noise if the little hole in front isn't pointing right at you. A knife is dangerous in more than one direction at once. I was going over some of this with my first Silat teacher (who just signed up for THR). He showed how a pretty simple pass or angling could be used in conjuction with the knife to disable the thumb, followed up with an attack to the neck. Maybe the gun will go off, but that second shot becomes pretty dicey and the chance of the first one hitting the target if the thumb is nearly severed is much reduced. The added distraction of a cut throat certainly increases the odds against the shooter.

[yy]

Thank you, John. (ahem)

thanks for all the comments. Good points.


John: I'm confused about the 180 pivot. I was thinking a little more than 90 degrees pivot as I step to the outside. Please clarify.


I'm curious about the blade on the thumb. It's certainly very merciful compared to what I had in mind -- a push cut starting from the wrist to the elbow, slice up the biceps, and keep moving to nik a throat before coming back out for a lung/armpit stab. (I'll remember the key MOVE, hso). At the end of my sidestep, I'll take that last stab while facing the opponent's side.

I thought this method ignored where the gun was pointing after the first deflection (maybe from the elbow). Not to mention that the traveling cut sure is vulnerable to clothing as hso pointed out.

I like the option where I take the pistol to the throat after turning the wrist and the elbow inward. This is more elegant and controls the muzzle to a better backstop.

I have a hardtime picturing how to do the above with my knife hand ...




Freddymac: will you ask your med-school gf a follow up question? What direction for the blade cut (push, thrust, slice, tip direction, etc) if you consider that the gun hand is moving -- so that the ulna (the arm bone next to the thumb) could rotate and deflect a blade? A dynamic push cut with the blade edge parallel to both the ulna and radius could be a little complicated with moving arms and rotating wrists and forearms.

[Kingcreek]

The problem with cutting tendons to disable is that muscles and tendons are a "one-way" mechanism. ie. there is no "reverse" but depends on opposing muscle groups to disengage or primary muscles to relax their action.
Cutting a muscle/tendon group would have to be a very clean and instantaneous severance or the very tension of cutting could cause the action you are trying to prevent.
also, those tendons are deeper than you might think from just digital palpation alone.
example: feel your scalp over the back of your skull and judge the depth of soft tissue. What feels like 1/8 inch is actually more like 1/2 inch deep.
IOW, you are not as close to those wrist and hand flexor tendons as you think. A knife attack to disable an armed opponent is a bad idea unless you have no other options.
Knife fights are messy business and not as effective as people might think.
-- so that the ulna (the arm bone next to the thumb) could rotate and deflect a blade?

The radius is next to the thumb. The ulna is on the side of the little finger.

[yy]

Thanks, Kingcreek. The radius is the one close to the thumb.

[JShirley]

Ian,

In the first move I describe, your setup after initial movement offline will put your chest to outside of attacker's arm. After you pivot, you'll end up facing the other way: 180'. If this is done well, with everthing locked into position, the attacker's wrist WILL break. There's just no way for it to catch up. Yes, I usually make a fetish in training of cutting the attacker's throat during this move, if we're practicing a knife disarm. No, the throat cut wouldn't probably be immediately fatal, since it mostly get the windpipe if done quickly, but it certainly would distract my attacker, helping me fulfill my goal of leaving as whole as possible.

I would have to have the love of the universe flowing through me to attempt to stop an attacker by merely covering their thumb with my blade. Yes, it can be done. No, I can't see myself doing it unless I had the love of God and an unnatural calm. It's not the type of thing I would suggest to others.

It's a good idea to think about reinforcing a single-edged blade to get the most return out of scraping the attacker's weapons away (especially if there's enough blade to reasonably do this). :) At the same time, simple is good. Getting outside as hso and I describe, then a very powerful stab to underside of arm or armpit, followed by the Nike triple-time to cover, is about as simple as it gets. The simpler the plan, the fewer the steps to go wrong.

John