When performing a straight punch (left or right) to the head, what is the best target for maximise the chance of knockout ?
A knockout occurs when the brain bounces around the braincase. This movement causes injury which will lead to unconsciousness.
In order to have a high chance of knocking the person out, the best place to target is the chin. This is both a relatively soft target, compared to other parts of the skull, and is relatively easy to get to. Impact there creates a lever effect that creates a lot of brain movement, which means a high chance for knockout.
There is a reason that boxers refer to easily knocked out people as having "a glass jaw".
A "knock-out" is loss of consciousness due to the brain making contact with the skull. The brain is surrounded by fluid and, normally, does not make contact with the skull. That contact is a traumatic event and the body can shut down.
The easiest way to cause this response is to "hook" the side of the chin, making the skull turn faster than the brain can follow.
With a straight punch, and with the assumption that you are facing an opponent who has his hands down and is just waiting for you to hit them, I really can't think of a good knock-out target.
Slightly behind either ear is the place to hit if you want a knockout. 43 years experience in martial arts, military and personal body guarding has proven this to me. As a former corrections officer, it is a statistical fact that knocking a person out rather than continuing to fight with them is a more humane way to end an altercation. The longer an altercation continues, the more likely you are to get hurt and/or inflict more damage on the other person. Most knockouts tend to cause less damage.
My personal philosophy is simple: I don't start fights, so if a person starts a fight with me, I plan to knock them out as quickly as possible to minimize damage to them and to me. If you don't want the horns don't mess with the bull.
I believe there are at least a couple methods of "knockout":
- brain is subjected to physical trauma inside your skull from quick accelerations
- not enough blood/oxygen is being supplied to the brain
Here are several potential examples of methods of knockout through disruption of blood flow or oxygen (best I could find at the moment):
If you follow your jaw back to where it joins the skull, the mandibular joint, you will see that it joins the head near the base of the ears (well, kinda near). If you place your fingers below the joint, you should be able to feel your pulse quite strongly.
Your fingers are directly over the carotid arteries. The carotids are the main arteries into the head, though you also have vertebral arteries going up your spine. But the carotids are the ones that are really interesting.
One carotid goes up each side, and branches near where your fingers are located into the inferior and superior carotid. At the junction, there is a physiologically important area that contains a large quantity of nerve endings.
These nerve endings sense some critical information about the blood before it goes gushing into your skull. It senses the oxygen content, possibly carbon dioxide content, and definitely blood pressure.
The receptors that check blood pressure at this branching point are called the carotid baroreceptors, and they are responsible for making sure you get plenty of the vino vitae into your brain. If blood pressure drops, they signal for an increase in heart rate and contractility, if the blood pressure rises, they signal the heart to slow down.
It just so happens that they really don't measure just blood pressure, but pressure on the notch. If you jab your finger right on top of this sensor, you can fool the sensor into thinking that it is your blood pressure that went through the roof, not that you're just pushing on the sensor itself. Then the body compensates by dropping blood pressure, which happens fairly rapidly.
Heart output drops, and you pass out from the pressure reduction in the brain.
Go ahead. Try it. Push real hard.
It is believed that a glass jawed person has a loose mandibular joint that allows a good solid thwack to cause a pressure wave that sets off the baroreceptor, lowering blood pressure, and down they go.
Grabbing the baroreceptor is also a common trick that the military and police use to subdue the proles. Punch a thumb into that area, and you'll put them to sleep right fast.
But . . .
There is a critical nerve that runs right next to this branching point of the carotid. This nerve, called the vagus nerve, is important for controlling heart rate and damn near everything else that happens below your neck. If this nerve is damaged, the immediate damage can cause the nerve to stop the heart, and if the nerve is permanantly damamged, you'll never shit right again, if ever.
Just thought you ought to know that before the teeming millions start thumb punching each other in the neck.
In my view, to best induce a knockout via a straight punch (as opposed to a hook or looping punch) while relatively face to face, the punch should be aimed at the chin to force the front of the head/mouth/chin down and the back of the jaw up into your skull for the best chance at disrupting blood flow through one of the methods given above. This also has the potential effect of throwing the person's head and body backwards, causing the person to back up, stumble, or fall.
If not face to face, and you are able to see/hit the side of his face, a straight punch aimed near the front of the chin will cause the most rotational acceleration/velocity in the jaw->skull->brain to cause trauma to the brain and induce rotational stress/strain on the brainstem.
Hitting the temple is also another choice (although I am not quite sure on that ones method of knockout, I will guess just plain physical trauma for now but could be a reaction to the nerves in that area, feel free to correct me!), but it is a "soft" spot on your head and is known to be potentially deadly. Take extra care in using this spot.
If you are able to hit the lower back of their head, you will be causing more direct trauma to the Occipital lobe which is the visual processing center for your brain, which can very likely cause a person to "black out". Hitting near the base of the head also causes trauma to the areas of the brain stem, which has a big part in regulation of the body's cardiac and respiratory function. Take extra care in using this spot.
Although you should "take care" in using ANY spot or hitting ANYONE in the head, there will be situations when you HAVE TO or SHOULD and is best to know of the potential options.
As has been mentioned by several others, Knockout punches/strikes can be extremely damaging or lethal to employ. They are not something to be played with. That said, there are three basic ideas behind a knockout strike (Chokes are a whole other animal).
The first and most common is concussion; the brain striking the inside of the skull. This depends mostly on accelerating the head more quickly than the brain can compensate. Here is a fairly informative article (and video) This kind of knockout works more effectively when the skull rotates after being struck. Although this question was specifically about a "Straight punch", that is probably not the best way to achieve a concussive knockout unless it is delivered side-on. For this sort of trauma I would recommend using a Hammer fist, as it generates good penetrative force, and allows striking the side of the head(which produces rotation).
The second kind of knockout is one using the arteries of the neck. This was covered in good detail by Zero.
Finally, the most debated kind of knockout strike, a nerve strike. Many styles and martial artists do not use, or even acknowledge this sort of thing, but it is taught (mostly as theory) in some styles. The idea is that by exactly striking specific nerves, you can overload the electrical signals to the brain causing seizure like shutdown. One of the most common(and least debated) targets is the "Accessory" nerve which runs behind the jaw, and down the neck. By utilizing precise strikes to this nerve, short term unconsciousness can occur. Whether or not your style teaches the use of these sorts of techniques, they would certainly be ineffective in the hands of someone who has not had decades of martial arts training.
Those are the only three methods of achieving a knockout strike I am familiar with, but each one is difficult to use without the level of training that would also make them fairly pointless to use. In short, planning a Knockout is probably not worth the effort it takes to execute.
I'm not too fond of this question, you should never want to knock someone out. Not even with boxing gloves. Knocking someone out is always tricky, as a K.O. is a result from brains bouncing back and forth (or extreme pain, but then it'd be rather called 'passing out').
Be especially careful with the temple. It's known to be a good knock-out hitting spot, but hitting someone's temple can actually kill the person. Don't EVER hit it!
As a sidenote, this site is about martial arts. The thing about any martial art, is that it has some thought, philosophy and morals behind it, and one of those morals is that you don't do brutal things like deliberately K.O.'ing someone.
Generally speaking, a straight punch is not optimal for causing a loss of consciousness. In boxing, most knockouts are caused by a solid uppercut punch to the chin (causing spine compression), or by a rapid flurry of straight/hooked blows (also causing spinal compression). Knocking someone unconscious is never a good thing, medically speaking.
Bare-knuckle boxers rarely ever knocked their opponents out, and that is because the amount of force required to render a healthy adult (of comparable size) unconscious is usually enough to seriously damage one's hands. It is feasible to incapacitate an opponent with strikes to soft tissue targets in a way that is comparable to being knocked out, but their are serious inherent risks there as well. A rapid combination of hard blows to the diaphragm, xiphoid process, and floating ribs can cause enough respiratory distress that a loss of consciousness is a possibility (and barring that is still pretty incapacitating). If safety isn't a concern (i.e. lethal force is warranted), rapid strikes (optimally open-hand or extended knuckle) to the throat can cause inflammation/swelling-induced asphyxia, but the throat is difficult to target (especially for multiple blows).
I've never used this but probably a hard palm strike to the forehead.
IMO Safe and controlled sparring should be practiced in order to perfect technique. Violent fight for pay should be banned along with dog fighting. Now street fighting for self or home defense is another issue all together.
Criminals rely on weapons and violence for their objective. For your safety perpetrators MUST be immpbilized as quickly as possible by either a knockout or limb break. If you don't do them FIRST, they WILL do you! Just my humble opinion!