# Knocking/rendering a person unconscious

**URL:** <https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317>\
**Category:** Factual Questions\
**Created:** [March 14, 2006, 3:06pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317 "2006-03-14T15:06:17Z")\
**Posts on this page:** 14\
**Page:** 1

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**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\
**Post date:** [March 14, 2006, 3:06pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/1 "2006-03-14T15:06:17Z")

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Inspired by this thread: [http://boards.straightdope.com/sdmb/showthread.php?t=362694](http://boards.straightdope.com/sdmb/showthread.php?t=362694)

It’s a movie/fiction cliche that you can “knock” an opponent/victim unconscious without killing him/her – and the unconscious person will eventually “come to” without even much of a headache. IRL, is there any way to do this? Any spot on the skull you can tap? What about drugs? Are there any reliable “knockout drops” that can be slipped into someone’s drink? Or do you need a professional anesthesiologist to safely administer anything that potent?

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**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\
**Post date:** [March 14, 2006, 3:16pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/2 "2006-03-14T15:16:08Z")

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I understand if you pinch the shoulder just right, you can do it.

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**Author:** ![athelas](https://avatars.discourse-cdn.com/v4/letter/a/5e9695/32.png) [@athelas](https://boards.straightdope.com/u/athelas)\
**Post date:** [March 14, 2006, 3:30pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/3 "2006-03-14T15:30:31Z")

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Only if you have pointy ears. The secret’s in the ears.

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**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\
**Post date:** [March 14, 2006, 3:49pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/4 "2006-03-14T15:49:06Z")

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You can’t cause unconsciousness in a person by hitting them on the head without causing some level of trauma to their brain. Now, I can’t personally deny that extreme precision in application to very narrowly mapped areas of a particular person’s brain could not provide a fairly reliable state of unconsciousness with an arguably minimal amount of permanent damage. It would take a ninja neurologist to have that level of expertise. I am not sure how common that specialty is.

And you still have damage. I had a head injury where I didn’t even loose consciousness, and seven years later, I still have cognitive function loss from it. (I can’t do arithmetic in my head, which I could do well up until that point. And my already poor memory recall for personal names reached truly embarrassing proportions.)

Concerning drugs, consider this: The most dangerous part of surgery is anesthesia. And that is with constant monitoring by a ninja anesthesiologist.

Tris

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**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\
**Post date:** [March 14, 2006, 3:55pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/5 "2006-03-14T15:55:01Z")

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A Straight Dope perennial.

Human beings don’t have an off switch. Any blow hard enough to knock someone unconscious has a very good chance of severely injuring them, possibly permanently, possibly killing them.

Sure, you can knock somebody out, it happens all the time in boxing. But even when a boxer crumples and hits the canvas he’s probably not completely unconscious, just stunned and unable to stand up. And if you kept pounding on his head until he’s completely unconscious he’s probably going to need immediate medical attention.

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**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\
**Post date:** [March 14, 2006, 4:41pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/6 "2006-03-14T16:41:54Z")

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In some of the old secret agent movies, the hero knocks out bad guys by hitting them on the neck with the edge of his hand. I’ve never understood why that would do anything other than bruise someone’s neck.

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**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\
**Post date:** [March 14, 2006, 4:59pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/7 "2006-03-14T16:59:36Z")

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> [@mks57](#):
>
> In some of the old secret agent movies, the hero knocks out bad guys by hitting them on the neck with the edge of his hand. I’ve never understood why that would do anything other than bruise someone’s neck.

Well, that’s the location of the brachial plexus, so potentially you could temporarily or permanently disable someone’s arm and shoulder with a blow like that. But it wouldn’t knock them out.

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**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\
**Post date:** [March 14, 2006, 5:06pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/8 "2006-03-14T17:06:23Z")

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It happened to me once in high school. A football player slugged me on the jaw. I immediately lost awareness of my surroundings. When I came to, I was slumped on the floor. I estimate I was out for maybe two or three seconds.

Now my brain damage is all over the SDMB…

When I was 11, a large thrown rock accidentally struck my forehead. The impact undoubtedly had much more force than the fist to my jaw. My blood flowed insanely and I got stitches at the ER. But it did not make me unconscious, not even a little bit.

Why a blow to the jaw can produce unconciousness, but not a much harder blow to the forehead, I have no idea.

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**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\
**Post date:** [March 14, 2006, 5:09pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/9 "2006-03-14T17:09:50Z")

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> [@Brain Wreck](#):
>
> Well, that’s the location of the brachial plexus, so potentially you could temporarily or permanently disable someone’s arm and shoulder with a blow like that. But it wouldn’t knock them out.

What if you hit the vagus nerve instead?

CMC fnord!

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**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\
**Post date:** [March 14, 2006, 5:20pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/10 "2006-03-14T17:20:53Z")

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> [@crowmanyclouds](#):
>
> What if you hit the vagus nerve instead?
> 
> CMC fnord!

I guess you could produce heart arrhythmia that way. I’ve heard men have made themselves faint by stimulating the vagus with the vibration of an electric shaver against the neck. But when you are talking about a blow to the vagus, you’re taking about a blow to the front aspect of the neck… I would be far more concerned about crushing the trachea in that case.

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**Author:** ![BarnOwl](https://avatars.discourse-cdn.com/v4/letter/b/e95f7d/32.png) [@BarnOwl](https://boards.straightdope.com/u/BarnOwl)\
**Post date:** [March 14, 2006, 5:23pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/11 "2006-03-14T17:23:40Z")

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Many years ago, I was in a bar I seldom frquented. TV was playing a Red Sox-Yankee game. The Sox scored, I muttered a mild, “How to go,” and the end result was the bartender slipped me a mickey.

In the early stages of my sensory decline, I had the good sense to call my wife and have her pick me up. I lay almost semiconscious on the back seat all the way home. Don’t remember anything after that.

And it wasn’t the booze. I had, at the very most, 2 drinks and they might have been beers.

So,I discovered knockout drops are for real. Chloral hydrate, is, I think the chemical name of KO drops.

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**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\
**Post date:** [March 14, 2006, 6:17pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/12 "2006-03-14T18:17:32Z")

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Yes, there are plenty of drugs that will knock you out. The trouble is getting the dosage exactly right. Too little and the victim just becomes woozy. Too much and the victim dies. And the correct dosage is highly variable for every person depending on body mass and physiology, and the dosage difference between an effective dose and a lethal dose varies as well. So if you regularly drug people with chloral hydrate you’re pretty likely to kill someone eventually.

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**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\
**Post date:** [March 14, 2006, 6:39pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/13 "2006-03-14T18:39:39Z")

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Here’s a [long and hard-to-read article](http://www.taijiworld.com/Articles/george.htm) about pressure points and knocking people out in martial arts.

A blurb from that article:

> [@](#):
>
> The neck striking is done with a knife edge pushing back into the carotid sinus with a beginning strike and then a sharp push into the artery, a small sinus behind the carotid artery which tells our brain when high or low blood pressure happens and acts accordingly. When struck, this artery (pressure point) tells us or rather fools us that extreme high blood pressure is present and so we faint. Any strike to this area will cause knock out regardless of how it is set up.

If you hit sharply enough on the front/side of the neck you can hit the right area to make someone faint, but it’s a seriously dangerous move because as **Brain Wreck** said, you can damage a person’s trachea or possibly kill them. If you’ve ever seen guys on TV specials knocking out a bunch of strong young men by chopping at their necks, this is what they’re doing.

The linked article has a lot of info on pressure points.

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**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\
**Post date:** [March 14, 2006, 6:49pm UTC](https://boards.straightdope.com/t/knocking-rendering-a-person-unconscious/348317/14 "2006-03-14T18:49:12Z")

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Well, if you don’t mind it being more of a grappling maneuver than a stricken blow, there’s unconsciousness via [Strangulation](http://en.wikipedia.org/wiki/strangle)

Apparently still not without risks, either that the victim will be faking, be able to recover some awareness as soon as you let up on the strangle, or will get strangled too far and die. But it seems relevant.
