Combative Anatomy: Using a knife for self defense

After writing the post about how to fight a dog, I got to thinking about how little information is freely available about using weapons in self defense against humans. Many people carry a pocket knife daily (I’ve carried one every day since I was nine years old), many of them with thoughts of using it as a defensive weapon if they needed to. But almost no one gives the actual how to use it part more than a passing thought. This is some basic information on how to use a knife as a defensive weapon.

Before I get started I need to get something out of the way.

1. Using a knife against another human is considered use of deadly force (even showing a knife is a crime in most places if it is not a clear cut case of self defense). If you would not be justified in shooting and killing the other person, don’t pull out the knife.
2. If you pull a knife in self defense, you need to be 110% committed to using it, quickly and violently. If you are not, do not pull out the knife.

WARNING:

This post is going to cover some very graphic information about causing massive trauma to another human with a sharp and pointy weapon. If you are at all squeamish, you probably don’t want to read any further.

DISCLAIMER:

I am not telling you to do anything here. This does not constitute legal advice. If you use any of this information in a situation other than self defense, you will go to prison.

Notice that the title of this post is “Using a knife for self defense”, not “How to fight with a knife”. Self defense is something you do when everything else has failed, and you are now in a fight for your life. Fighting with a knife is something you do just before going to prison. Even if you are 100% justified in using a knife as a defensive weapon, you are probably going to have legal troubles because of it, and you are definitely going to have psychological troubles because of it.

This is not a post about conflict resolution, or violence deterrence or avoidance. These are your first lines of defense. This post covers what to do when everything has failed, and you are in a fight for your life against another human (or multiple attackers). This is not going to be nice, it is going to be extremely graphic.

If you’re still reading, I hope this information can be used to save your life if you are ever in the unenviable situation of having to fight for your life, but the information in this post is not going to do it all by itself. Physical combat is something that must be trained and practiced if you want to perform any better than half-assed (at best). If you carry a knife for self defense, I highly urge you to get some training on how to use it properly. In the realm of knife use I think Tom Sotis’ AMOK! system is about the best training you can find.

If you carry a knife for self defense you need to ask yourself a very serious question; can I cut/stab another human, possibly resulting in their death?

Using a knife as a weapon is very intimate, you are going to be very close to the damage you cause. You are going to be traumatized by it.

You need to know that if you use a knife on a human, you are going to see a LOT of blood, and probably a good sliced open chunk of meat. If you want to know what a real knife wound looks like (this is really, really graphic) take a look at some of the images here.

Could you do that to another human if your life is on the line? Only you can answer that question, but you must answer that question if you are going to carry a knife as a defensive weapon.

It is rather easy to think that you could, but I know men who have shot people and tell me that they could never use a knife on another person.

The concept I am trying to convey is very difficult to communicate correctly. There is a lot of macho “I could totally cut that guy up” crap that you need to put aside, and really consider what the consequences of you actions (or potential actions) are. Marc MacYoung (who knows a thing or two about self defense) really sums it up well in this post on his website. I really urge you to read that and understand that there are rather steep costs to using a knife against another person.

Just something to think about.

Let’s get started with some basic anatomy:

Click to enlarge

Anyone who has taken anatomy in college (or in high school even) will be able to tell that this is not 100% accurate and to scale, but it is close enough for our purposes. If you really want to get a strong grasp of where vital targets are on a human, pick up a copy of Gray’s Anatomy (paperback is your best bet here).

Unlike when fighting a dog, humans have a deep and instinctive fear of knives. It is possible that simply brandishing a blade will cause your attacker to have a change of mind, and suddenly remember that he has something else that urgently requires his immediate attention, but I would not rely on that. I prefer that an attacker not know that I am armed until I am using whatever weapon it may be on them. Just be aware that brandishing, while it may effectively deter the attack, is generally also a crime.

If you decide to show the attacker that you are armed and they back off, you should do two things immediately:

• Leave the area.
• Call the police to report what just happened.

You need to leave because criminals have a funny way of deciding that your knife wasn’t quite so scary when they get somewhere where they can get reinforcements or other weapons, neither of which is usually far away from where they choose to commit their crimes.

You need to call the police and report the incident so that the attacker who you just scared off doesn’t have a stroke of “genius” and decide to call the police and report that you threatened him with a knife while he was helping an old lady to cross the street (which has happened more than once).

When using a knife for self defense you have two basic strikes; slash and stab.

Slashing targets

Figure 1 – Click to enlarge

Figure 2 – Click to enlarge

Figure 3

Since the human body is (more or less) symmetrical, the targets shown are in the same place (roughly) on either the left or right side of the body.

Point A in Figure 1 is the Superficial Temporal Artery which runs along the outside of the skull across the temple (shown better in Figure 2). If cut this will bleed profusely.

Point B in Figure 1 is the side of the neck and throat just about even with the adam’s apple. This area contains the Carotid Artery and Jugular Vein. If either is cut the attacker will bleed to death very rapidly. The Carotid is approximately 1.5″ below the surface of the skin, so a powerful slash will be needed to reach it, however if severed unconsciousness will result in approximately 5-15 seconds (assuming no chemical stimulation). Be wary, as drugged up attackers may continue to fight on for up to a full minute.

Point C in Figure 1 is the trapezius muscle. This muscle is responsible for much of the shoulder movement.

Point D in Figure 1 is a cut to the outer side of the pectoral muscle. This should be a powerful slash. If done horizontally and continued out to the arm it can potentially sever the cephalic vein which will bleed profusely.

Point E in Figure 1 is a cut across the front of the deltoid muscle. If done powerfully it may sever the cephalic vein.

Point F in Figure 1 is a slashing cut across the biceps. This muscle is responsible for much of the motion of the arm and contains multiple veins.

Point G in Figure 1 is a slashing cut across the inside of the elbow joint. In addition to the numerous veins (shown as point B in Figure 3), this area also contains the ligaments that enable motion in the forearm.

Point H in Figure 1 is a horizontal cut across the forehead. This area is dense with veins, and will bleed profusely when cut, potentially blinding your attacker.

Point I in Figure 1 is a vertical cut across the cheek and jaw. This area contains some of the major nerves in the face and will be extremely painful.

Point J in Figure 1 is a horizontal cut across the neck and throat. This area contains not only the Jugular Vein, but the trachea and ligaments that control movement of the head.

Point K in Figure 1 is the trapezius muscle closer to the neck.

Point L in Figure 1 is a powerful slash across the pectoral muscle. A deep cut here will destroy the attacker’s ability to throw punches with any power behind them.

Point M in Figure 1 is a powerful vertical slash to the abdomen. Successful penetration of the abdominal wall here will result in loss of motion, and possible disembowelment.

Point N in Figure 1 is a powerful horizontal slash to the abdomen. Successful penetration of the abdominal wall here will result in loss of motion, and possible disembowelment.

Point O in Figure 1 is a penetrating slash to the inside of the forearm between the radius and ulna bones. Penetration of more then one inch will sever a great deal of veins (shown as Point C in Figure 3)and result in rapid blood loss.

Point P in Figure 1 is a slash across the back of the head starting at the top rear of the ear and ending near the center of the skull. There is a group of minor arteries that run across the outside of the skull here (shown in Figure 2), and will bleed profusely if severed.

Point Q in Figure 1 is a slash across the outside edge of the shoulder blade, and will result in loss of motion in the shoulder.

Point R in Figure 1 is a vertical slash down the back between the spine and shoulder blade. This group of muscles is responsible for much of the motion of the upper torso.

Point S in Figure 1 is a vertical slash across the rib cage and kidney area. This will be extremely painful and result in loss of motion.

Point T in Figure 1 is a horizontal slash across the back of the neck. In addition to the numerous veins here, these muscles control much of the motion of the head.

Point U in Figure 1 is a slash to the rear of the trapezius muscle which will result in loss of motion in the shoulder.

Point V in Figure 1 is a slash through the muscles in the back between the lower edge of the shoulder blade and spine, curving to follow the shoulder blade. This will be extremely painful and result in loss of motion in the upper torso.

Point W in Figure 1 is a horizontal cut across the lower back. This area is highly dense with nerves and will result in massive pain and loss of motion in the upper torso.

Figure 2 gives a better view of arterial structure in the head and neck.

Point A in Figure 3 is the brachial artery that runs along the inside of the arm. This artery is deep, but severing it will result in unconsciousness in as little as 15 seconds, and death in as little as 90 seconds.

Point C in Figure 3 is the radial artery (this artery runs across the top of the radius bone 2-4 inches behind the base of your thumb). Severing the radial artery can result in unconsciousness in as little as 30 seconds, and death in as little as two minutes.

Stabbing targets

Figure 4 – Click to enlarge

Point A in Figure 4 is the side of the neck just behind the adams apple, approximately 2-2.5 inches from the front of the throat. This is ideally a thrust with the blade perpendicular to the spine, and cutting out the front of the neck. If done correctly this will sever the carotid and trachea, resulting in loss of consciousness in as little as 5 seconds and death in as little as 12 seconds.

Point B in Figure 4 is the inside of the right armpit, with the blade parallel to the ribs. If done correctly this will pass between the 3rd and 4th rib perforating the right lung. This is a risky target due to potential for the blade to bind in the ribcage.

Point C in Figure 4 is a thrust up and under the right side of the ribcage, done at a 45 degree angle into the liver. Depending on the severity of the damage to the liver this can result in unconsciousness in as little as 1 minute, and death in as little as 5 minutes.

Point D in Figure 4 is the subclavian artery located approximately 2.5 inches below the point shown, just behind the collar bone. Severing of the subclavian artery will result in unconsciousness in as little as 2 seconds, and death in as little as 3.5 seconds.

Point E in Figure 4 is the inside of the left armpit, with the blade parallel to the ribs. If done correctly the thrust will pass between the 3rd and 4th rib perforating the left lung and the heart if the blade is of sufficient length (documented cases of blades as small as 3.5 inches successfully piercing the heart exist). Piercing the heart can result in instant unconsciousness and death in as little as 3 seconds. This is a risky target due to potential for the blade to bind in the ribcage.

Point F in Figure 4 is the center of the abdomen, approximately 1 to 4 inches above the navel. Approximately 5 inches below the skin is the Descending Aorta (the largest artery in the body) and Inferior Vena Cava (the largest vein in the body). Severing either can result in unconsciousness in as little as 1-2 seconds and death in as little as 3-5 seconds.

Point G in Figure 4 is just behind the bottom of the ear. This hollow is the only point that an average person may be able to pierce the skull with a knife. Long narrow blades have the best chance of reaching the brain. A solid thrust here can result in instantaneous death. This is a risky target due to potential for the blade to bind in the skull (or jaw if done incorrectly).

Point H in Figure 4 is a thrust to either kidney. Puncturing a kidney can cause near instant unconsciousness, and death within as little as one minute. The Kidneys are connected to the body by the Suprarenal veins, which are rather large, so even if the kidney is not punctured, a thrust here may still sever one of these and result in rapid loss of consciousness.

Considerations

Carrying a pocket knife, and carrying a pocket knife with the express intent to be able to use it as a self defense tool are two completely different things. Until I was about 15 I carried a swiss army type of knife in the bottom of one of my pockets. This is going to be almost useless in a situation where you will need a knife as a self defense tool. Chances are, if you need to use a knife in self defense, you are going to need to have the knife open and in your hand about 5 seconds ago.

Some things you’ll want to consider if you are carrying a knife for self defense:

• How quick can you get the knife open and in your hand?
• Can you open the knife with one hand?
• Can you reach the knife with either hand?
• Can you deploy the knife if someone grabs you from behind and pins both of your arms to your sides?

In another post I’ll cover the criteria that I use to select a knife that may be used as a defensive tool.