Depth to kidneys?

[EnglishmanInArizona]

Apologies for a relatively ugly question.

What length of blade is considered a reasonable minimum for reaching the kidneys, from behind?

I'm aware that a blade can penetrate deeper than it's length due to compression, but I would rather leave that out of things as too variable.

 

[highorder]

I think that's outside the scope of our forum.

A quick google human body will answer your questions.

 

[Texan Scott]

hmmm... well, it's a non-firearms WEAPON, i suppose... if we can discuss shooting people in the context of guns, i'm not sure why stabbing (in the context of knives) is off limits.
The answer to your question is probably a) depends on the person, b) depends on what they're wearing, c) keep in mind you need to not only reach the kidney, but through it, d) width of the blade is as important as length, e) 5 inches. (LOL, thats a wag... but a 5-inch knife is not a small knife.) and finally f) ummm.... why do you ask?

 

[Owen Sparks]

They are not very deep at all, just under the 11th and 12th ribs.

 

[EnglishmanInArizona]

Well, to justify the question - the kidneys are a particularly good target for a rapid stop with a blade. Fighting within any system that emphasizes movement off the opponent's line of attack gives a reasonable probability of rear targets being open. Also, if pressed body to body, as in a pin, rear targets may be easier to access than front, particularly if the blade is being drawn from around the beltline or a pocket.

This is not an assassination question.

A quick Google search is not actually such a great source for something like this. It appears to me that the kidneys are under 2-3 inches of muscle depending upon angle, but I am really not sure that this corresponds to a 3-4 inch blade.

 

[EnglishmanInArizona]

Cross posted. Thanks to those offering answers.

 

[glistam]

Bad sign when "rapid stop" and "blade" appear in the same sentence. Even bullets to the kidney don't necessarily cause "rapid stop."
http://www.ncbi.nlm.nih.gov/pubmed/18210067

Only literature I have seen that advocated thrusts to the kidney are sentry-removal texts. And that isn't all that useful for self-defense.

 

[EnglishmanInArizona]

Bad sign when "rapid stop" and "blade" appear in the same sentence. Even bullets to the kidney don't necessarily cause "rapid stop."

"Rapid" is very relative in this case. That abstract also only demonstrates that the individual survived. It gives no indication of whether he was stopped. I'm not using "stop" as a euphemism for "kill" here.

Only literature I have seen that advocated thrusts to the kidney are sentry-removal texts. And that isn't all that useful for self-defense.

It's not just in sentry removal texts, but the reason they advocate thrusts to the kidney is because of the high likelihood of serious, instantaneous shock, creating TIME to do whatever is next, usually cut the throat in that context.

In self defence, time is equally valuable. That moment created by shock may be enough to escape a pin, to run away, or to do some other type of damage to an opponent.

The biomechanical/bleeding/organ shock argument has been going on for a long time, I'm not looking to go over it again. If it ever came down to it, I'd be looking to hedge my bets and go for all three. A stab to and cut out from the kidney hits two of those approaches.

 

[Odd Job]

Here you go:



This is an adult male with a fair amount of muscle and fat.
Skin to renal capsule, short distance is 6cm.
Skin to renal artery or renal pelvis is around 9cm.
If you don't have a straight shot, then you can be looking at 10cm to hit something vital on a kidney.

 

[EnglishmanInArizona]

Thank you Odd Job!

That's exactly the kind of info I was looking for, and the detail on sex and build was really useful. I could have been estimating off a section from a 90lb woman and had no idea.

Looks like 3" barely stands a chance, 4" is a realistic minimum then, and 5" would definitely be an improvement, particularly if someone is heavily muscled or just plain fat - or both. Looks like Texan Scott's WAG was about right. As he says, not a small knife by EDC standards, and it's got to be in as far as it will go.

Thanks again.

 

[hso]

Not at all. http://www.thehighroad.org/archive/index.php/t-13892.html

The problem is that there are very few SD opportunities to stab to the kidney.

 

[EnglishmanInArizona]

The problem is that there are very few SD opportunities to stab to the kidney.

Probably so. In the rare event, however, it would be good to know whether it's worth trying, or if it's better to use your time trying something else.

I note from the other thread someone states 5-10 seconds for a good stab to the kidneys to take someone down. If that's true - that is pretty fast for a knife wound, and seems well worth having as an option. If you also get a stunning effect, then it seems excellent.

Thanks again for the inputs from people.

 

[Texan Scott]

It's a rare opportunity I'd be happy to never have, yeah... and "rapid stop" and "blade" don't sound good together, no... but if (God forbid) your life, your last and only hope for ever again seeing the loved ones who think you're running to the corner for a loaf of bread, ever depend on it.... English, do all the damage you can, keep doing it, and pray it works....

 

[Gordon]

7" attack blade length was not just pulled out of the air!

 

[AStone]

And if all else fails, jugulars, carotids
and trachea are not nearly so deep.

 

[Texan Scott]

My teeth aren't all that sharp.

 

[EnglishmanInArizona]

7" attack blade length was not just pulled out of the air!

I think there are a LOT of reasons that 7" is an ideal length (said the actress to the Bishop).

Unfortunately, many of us cannot carry a 7" knife with us as an EDC. For me, I am able to carry anything under 5" onto university grounds (an environment where I cannot carry a gun) - and information in this thread shows that the kidneys, a target I have been taught, is still a very viable target with a blade that pushes to the limits of that envelope. It's not a viable target with my current pocket knife.

And if all else fails, jugulars, carotids
and trachea are not nearly so deep.

Yes indeed, and probably as rapid as can be achieved with a knife. A generally preferable target, especially with your new ESEE 3 Your enthusiasm about it is quite contagious.

 

[9mmepiphany]

Probably so. In the rare event, however, it would be good to know whether it's worth trying, or if it's better to use your time trying something else.

It is not, it is better to try something else

I note from the other thread someone states 5-10 seconds for a good stab to the kidneys to take someone down. If that's true - that is pretty fast for a knife wound, and seems well worth having as an option. If you also get a stunning effect, then it seems excellent.

It isn't as fast as you might think. 5-10 seconds is a lifetime in a fight...I can accurately empty a 15 round magazine and reload in 5 seconds...a long fight is one lasting more than 15 seconds

In a face-to-face knife encounter, you'd be better served by removing your attacker's ability to grasp their weapon, raise their arm and support their body weight.

I have personally witnessed more fights involving blades than I'd care to remember and seen live footage of more. The kidneys aren't really a practical target, except for sentry removal

Fighting within any system that emphasizes movement off the opponent's line of attack gives a reasonable probability of rear targets being open.

Systems that I have experience in, have taught to have completed at least 2 cuts before you even get there...you're attacker wouldn't be standing at that point, much less holding a weapon

 

[AStone]

Your enthusiasm about it is quite contagious.

And genuine.

Read 9mm's advice ^,
along with JShirley, Hso and Conwict,
and check out the 3"ers.

 

[EnglishmanInArizona]

Thank you 9mm. Your experience is valued.

Systems that I have experience in have taught to have completed at least 2 cuts before you even get there

Likewise.

In your opinion, then, if you do find yourself in the advantageous position of being practically behind them, having already made at least two cuts, you would go for the throat? That's been my preference in practice, and I generally find that my knife is high at that point anyway and the throat is also the nearest target. There are just a few situations where I tend to find the kidneys the more immediate target, and given their use in sentry takeouts I am loath to dismiss them.

In a face-to-face knife encounter, you'd be better served by removing your attacker's ability to grasp their weapon, rise their arm and support their body weight.

Clearly you favour the biomechanical cutting approach. Of the three approaches it is the only one I don't doubt the theory of, because no matter how much adrenalin, amphetamine or whatever else is in someone's system, if tendons are no longer connected they will not work. Period. All that I do doubt is the practical application - my/your/someotherguy's ability to effectively make those cuts with a relatively short blade. For everyone who says it is feasible, someone else says it is not. If you have seen it working with EDC sized knives, I would really like to know.

I started out with cutting swords. Biomechanical cutting is obvious in that case. If I was using a 12" knife I wouldn't be concerned, either. Using a 5" knife - it ain't much to slice with.

5-10 seconds is a lifetime in a fight

Agreed. For a single wound, though, it seems quite fast. In a multiple opponent situation (which is, for me, the most likely situation in which I wouldn't be able to run away) where I don't have the luxury of continuing to press the advantage over a single opponent, it seems valuable.

Admittedly, a multiple opponent situation is seriously bad, but it really does seem the most likely situation in which my knife is drawn. It's the situation in which I am most likely to have it concealed in my hand before anything kicks off.

As said above, experience is valued, and I'd appreciate comments.

 

[AStone]

My suggestion in the middle of this blade talk is this.

Make sure at least one of your hands holds a 16 - 20" stick.

For me, it's my left hand. The stick blocks,
breaks a hand or arm, then reverses direction
to cap a knee from the inside. Something like this.

If necessary, the knife slashes or stabs.

 

[9mmepiphany]

After the two cuts and now being behind my attacker, my next move would be to escape or move on to the next attacker. In MBC, my last cut is leaves the blade low...having just taken the quad. The technique was based on using a 3" blade...which will go though any arm or leg muscle to the bone. A longer blade takes a different technique, but you really aren't at much of a disadvantage with a 5" blade...plus it is easier to reverse blade orientation and grip.

I've only worked against multiple opponents in practice melees and I'm getting the same 3 basic cuts in as I step through each one...bagua footwork and body motion help. Another advantage of stepping into your attacker is that it limits the targets you offer the other attackers. The short blade needs to be used with a different mind set than a long blade...it isn't about holding them at bay and trading strikes and parries. I can't even imagine engaging and only making a single cut

 

[Jason_G]

7" attack blade length was not just pulled out of the air!

Unfortunately, many of us cannot carry a 7" knife with us as an EDC. For me, I am able to carry anything under 5" onto university grounds (an environment where I cannot carry a gun)

Double check to make sure that they aren't referring to overall length of the entire knife when they say 5". I may be wrong, but a 5" blade sounds awfully lenient for most college settings. I suppose if kitchen knives are allowed in dorms, and there is no special exception for dorm rooms, then it is possible that they allow such a long blade, but again, I'd double check if I were you. Where I went to school (at two different colleges), the blade couldn't be more than 2.5", IIRC, and there was an OAL limit too, if my memory serves me correctly.

Silly that there's a perceived need for such laws, but I wouldn't want you to get in trouble with your school or the law. If you're sure you are reading it correctly, then I apologize for being so nosy.


Jason

 

[JShirley]

I can accurately empty a 15 round magazine and reload in 5 seconds

9mm is a better handgun shot than I am in general, but I'm pretty sure I can beat him on a mag dump, probably accompanied by getting offline simultaneously. (I was next to the shooter who took top honors out of 60 students in our Gunsite class, and handily outshot him on non-traditional responses.)

After 2 cuts to get behind an attacker (wrist/forearm, leg or side of stomach, for example), if I didn't immediately have to defend against someone else, I would tend to give a quick kidney-aimed jab to reduce the chance the attacker could continue to attack/pursue me.

you're attacker wouldn't be standing at that point, much less holding a weapon

Unfortunately, while this would be my hope, if I'm responding at lightning speed with a sub-4" blade, I wouldn't count on it being true. If nothing else, I will have moved too fast for my attacker to fall, and I'm not going to wait to see if my slashes have been effective. I'm going to fight until there's no threat, I can get away, or the lights go out. Further, that kidney stab will push my attacker away from me, or if I'm scared enough and there aren't other assailants- and the attacker is wearing appropriate clothing- I can grab his collar and put more stabs in until he realizes the universe wants him to stop trying to hurt me.

John

 

[hso]

The kidneys aren't really a practical target, except for sentry removal

That's a very true statement.

From a SD standpoint there's almost no chance the depth to the kidney is relevant.

From the historical standpoint there might be some interest in the various military sentry removal philosophies.