Location, depth, and type factor into the lethality of knife wounds. A blade in the brain may miss your major blood vessels and functions. (source)
Getting the Point Knife Wounds & You – Pt 2 Location, Location, Location! Written by Corey O; Audio By Jonathan Fader

Location, Location, Location!

This post introduces even more to consider with regard to the results of “successful” knife attacks. If this gives you pause, as it should, perhaps it is time to checkout the self-defence training available in your area? Sure, water landings are unlikely during air travel, but they still dedicate space in the safety card to explain what action to take during one.

As the title would imply, the location of your sharp force trauma is a key factor in your survival as well as the severity of any lasting effects. But “location” covers more than simply the placement of a pointy object in your body. Given the fact that our physical reality involves three dimensions, you also have to consider how deeply the blade penetrates at the sight of contact. A knife penetrating the area of your chest over your heart is far less concerning than one which reaches in to pierce it. In addition, you need to be concerned with whether you’ve been stabbed or slashed.

Location – A stab or slash will be far worse if it strikes a sensitive area. “But, wait!” you say, “I’m covered in sensitive areas!” That’s absolutely true, as I will discuss in excruciating detail below, which is why learning to deal with knife attacks is so important to any self-defence education. Not only are you going to have a better or worse time based on the specific point on your outer body that is struck, the rest of your day will unfold differently based on what is under the surface of that point, as well as how large the wound turns out to be. You are dealing with a different timeline depending on whether the jab is to a vein or an artery, and whether it was a small hole versus a long opening in that vein/artery.

Depth – How deeply the blade penetrates will determine what damage is done: Does it just cut into your fat layer? Does it reach in to poke your liver? Does it drive deeply enough to cut your liver in half? Even if you are lucky enough to have your internal organs spared, a deeper stab or slash will, by its very nature, expose more blood vessels, or larger sections of a single vessel, and therefore potentially increase your rate of blood loss.

One saving grace in regard to depth is the presence of bone. Assuming you have maintained a healthy calcium intake and are not suffering from osteoporosis (or osteogenesis imperfecta), your bones will stop a blade far more effectively than your soft tissues. Unfortunately, everything has a downside and that same life-saving bone structure will hinder your attempts to apply pressure to bleeds within a deep chest wound (ie. your ribcage will get in the way of putting pressure on an internal stomach wound).

Stab vs Slash – A jab that creates a 2cm hole in a vein is not ideal, but could still be manageable. Whereas the same blade dragged across the same vein, this time opening a 10cm slit, will have a greater impact on your ability to keep your blood within the confines of your body. Penetrating injuries are going to cause all manner of internal nastiness, some which you may not even be aware of until someone (hopefully a trained physician) takes a look on the inside. What kind of shape you are in on account of a stab will depend on the length of the blade; a linoleum knife isn’t going to “bleed ya deep” from a thrusting strike, but it will leave a trail of red and pain if drawn across your torso.

We must also consider that slashes, while in most cases not directly interacting with your inner vitals, may wreak havoc on your muscle tissue. Muscles that are no longer attached will be less-than-useful for operating your limbs. A reduction in limb function has a casual relationship with a reduction in self-defence efficiency and, if experienced in the lower body, escape speed.

In the following section I’m going to go into a LOT of detail about vascular/muscular/skeletal anatomy, feel free to skip or memorize a given section based on your personal interests. (Though I suggest you at least take a peek at the chest and abdomen sections, as they make up a large set of relatively static targets on your body)

Extra Credit Anatomy Lesson:

  • Head – If you take a stab to the base of the skull into the brain stem, it’s lights out. This also applies to any blade entering you above or between the atlas and axis, which are the thin cervical vertebrae (C1&2) connecting your noggin to your neck. Your head has a few arteries running along its surface; the superficial temporal runs upward along the side of your skull, and the occipital is located at the base of your skull around the back. Slashes to either of those, while not terribly deep, can give you problems without even penetrating the skull.
    • Eyes – Your lookin’-balls are deeply connected to your evolutionary psychology, if you damage or lose one you’ll likely be in a panic. Beyond that you will find yourself operating without the benefit of depth perception. Perhaps the stabby object is long enough to break through the back of your orbit (eye socket), if so, your brain is right behind that thin wall of bone. If the attacker is really accurate, or you are really unlucky, the offending object may avoid bone altogether by keyholing straight through your superior orbital fissure, the gap at the back of your orbit through which several veins and nerves, including the optical ones, pass.
    • Face – Depending on severity of the slash there might not be any beauty contests in your future. The skin of the face is full of capillaries, therefore damage to the cheeks and forehead may not be lethal, but they tend to get messy. “Messy” could easily turn to “debilitating” if a slash to the forehead or above the eye results in blood blurring your vision. If you are slashed along the jawline the blade may open your (aptly named) facial artery. Further up the jaw is your maxillary artery which also has branches terminating in the area of your cheek below your eye, on either side of your nose. Taking a slash or stab from underneath isn’t good, as under the jaw hides your lingual artery. These are relatively small arteries, so the bleed out rate isn’t going to be severe, but will still require attention. That being said, penetrating injuries here are going to have bad results for you, seeing as the brain is accessible from several angles. Even without touching grey matter, a stiletto up the nose is going to wreak havoc on your sinuses, leaving your various conches, sphenoids, and ethmoids in hella disarray. Any sharp object entering your mouth that doesn’t connect with your teeth and gums can be assumed to be taking a shortcut to your brain and may find your internal carotid artery along the way.
    • Brain – Sure, some people survive cerebral jabs, but, as a general rule, anything stuck into your brain is going to manifest severe consequences. Be it nervous system disruption or bodily function failure, you will be diminished in some capacity, assuming you live.
  • Neck – Major arteries on both sides, as well as large veins! Your carotid arteries run upward along each side of your trachea and around/below your jaw; so they are very likely to be affected by any sharp edge that is ripping through that space. These are the “5-15sec to bleed out” type of wounds! If your throat is slashed, there can be all manner of damage to your wind pipe (trachea), and you find yourself aspirating blood and therefore unable to defend yourself. Fortunately, if you are lucky, thyroid cartilage and cricoid cartilage could help you out by acting as a shield, but you shouldn’t rely on that; get trained! However, if a stab enters your airway through the side, those small bone-wannabes are useless; so get trained! Also worth consideration is that, in addition to the blood vessels, slashes to your neck could damage the various muscles and ligaments by which you move your head; which leads to some obvious difficulties and detriments. Finally, if someone sticks a knife between any two of your vertebrae, cervical 1-7 in this area, you are experiencing paralysis at best, death at worst.
  • Shoulder – There are three heads on your deltoid, a slash to any of them means a loss of range of motion for that arm. Deeper cuts may open the proximal (upper) end of your cephalic vein on the outside or brachial artery on the inside, both leading into your bicep. If a stab from above gets you a little further toward your neck it will threaten your subclavian vein, just behind your clavicle (collarbone). If they are striking you from below and manage to land a stab in your armpit, not only will it be painful and problematic due to the presence of the brachial plexus nerve bundle, your axillary artery also dwells here (and we know to avoid arterial bleeding)
  • Upper Arm – A deep bicep slash means you are now defending yourself, or addressing wounds, with one less arm. You also have to worry about the, now more accessible, brachial artery nestled in this part of the arm.
  • Lower Arm – You are likely to receive some slashes on your forearms, as throwing your hands out in front of you tends to be the natural human defensive reaction. The placement of these wounds can be the difference between life and death: Your arm bones, the radius and ulna, protect many of the vitals on the lateral (back or outside) portion of your arm. However, on the medial (inside) a blade will have unfettered access to the radial artery and ulnar artery.
  • Hands – Other than metacarpals 2-5, you palm is soft tissue, so any knife long enough to be worth stabbing someone with is pretty much guaranteed to pierce straight through your hands. The cause for concern is that the soft tissue in question is full of several small palmar arteries (proper digital, common digital, superficial arch, deep arch) as well as the princeps pollicis artery and the plainly named radial artery of the index finger. The tendons that animate your fingers also hang out here, therefore a sharp object entering (and exiting) has a good chance of severing something, thus rendering one or more fingers unusable and diminishing the overall quality of your penmanship. Your wrist, on the other hand, (well… both hands…) is more densely packed, housing nine carpal bones and the distal end of the radial and ulnar arteries.
  • Chest
    • Aorta – This is the big one! Literally. The aorta is the largest artery in the body and acts as the major pathway for blood from the heart to reach everything else. The aorta is somewhat safely buried under all your viscera, running along your spine (slightly off to the left) and giving it a hug with several Radiculo-medullary arteries along the way. If something reaches in to touch your aorta, even nicking it, you won’t have much to time get to a hospital. There are a lot of places on the torso where a knife, driven deep enough, could find your aorta, as it is made up of three sections:
      • Ascending aorta: Exits the top of the heart, from the left ventricle, wraps over and down (called the aortic arch) to descend behind the heart.
      • Descending thoracic aorta: Upper part of the aorta from which the various spinal arteries branch off in order to feed the spinal column.
      • Abdominal aorta: The source of blood for most of your internal organs, which makes it important. Branching into the two iliac arteries in the innominate (pelvis)
    • Lungs – A stab to the chest can easily result in a collapsed lung (pneumothorax), ie. the air you breathe in is escaping into a pocket outside of the lungs. You will experience a shortness of breath and it will get progressively worse as time passes. Plus, you are bleeding internally!
    • Heart – Your heart isn’t completely behind bone. Your sternum, which is ~17cm long and runs down the middle of your ribcage, only protects about half of it; as the heart sits slightly to the left of centre. Thus your precious blood pump is accessible to assailants (and lovers) through the ~15-20mm gaps (intercostal spaces) between your 1st, 2nd, 3rd, 4th, and 5th ribs. Yes, a wide kitchen knife could be stopped by being caught on the ribs above and below each gap, but if the knife is coming in flat that is irrelevant. It is worth mentioning that the heart isn’t super deep in there, only ~32-70mm for most people, so I wouldn’t bank on an “intercostal save” regardless (maybe bulk them pecs for extra shielding?) If your heart is damaged you are in rough shape due to the plethora of things that can go wrong. First off, if you are struck in a pressurized cavity of the heart it will lead to the blood being forced out of the hole rather than into your aorta and off to sunnier destinations around your vascular system. Barring that, any damage to the muscle itself will reduce its ability to maintain your blood pressure. Even a near miss could tag one of the many vital vessel surrounding your heart, for example:
      • Coronary arteries which supply blood to the heart muscle itself.
      • Pulmonary artery takes blood from the heart to the lungs to be oxygenated.
      • Pulmonary veins move oxygenated blood from the lungs to the heart for distribution.
    • Spine – A large section of the spine is located here, your thoracic 1-12 vertebrae, we want to avoid anything entering between said vertebrae, and those protect the spinal cord. The postural spinal artery and anterior spinal artery can be found up here. So if the bladed object misses your spinal cord, hitting either artery is still going to lead to not just the predictable hazards of overall blood loss, but also the specific knock-on effects of these arteries’ blood having been destined to feed nerve tissue that is “sensitive to ischemia (lack of blood supply), and… can be damaged or killed by the interruption of the blood supply.”
  • Abdomen – Lots of potential for direct organ damage here, some of it disruptive to your system, some of it outright deadly. The really bad news: Internal fluids are enclosed in specialized sacks for a reason, if they are punctured several ugly processes take place. Digestive juices from the stomach may lead to (mild) acidic burns or infection, alkaline enzymes in several organs could cause saponification of neighbouring fatty tissues, and various bio-flora of the intestines and stomach will run wild in your gut, leading to septicemia (bacterial blood poisoning).
    • Kidneys – As far as bleeding out is concerned, the kidneys contain a lot of blood vessels and are a “blood rich” organ, as they are meant to filter your blood. In addition, you have two important tubes present; the renal artery bringing blood in for filtering and the renal vein ferrying the clean blood back out.
    • Liver – Your liver is responsible for several hundred important functions, it is also a fairly large target compared to the other internal organs. The liver is densely packed with blood vessels, so internal bleeding is guaranteed. You may also suffer full-body nervous disruption effects similar to those of a “liver shot.
    • Spine – This area is where we find the bottom of the spine, the last two thoracic (T11&12) and you five lumbar (L1-5), so attacks from behind have the double benefit of introducing the risk of spinal cord damage along with your bloodletting.
  • Groin – Here we find the lower part of iliac artery and upper section of femoral artery, both of which you don’t want to compromise as they branch directly off of the aorta and will lead to a “speedy bleedy.” If you take a knife to the genitals you may survive (are you sure you want to?), as the arteries found there are relatively small (walking may be difficult).
  • Thigh – The biggest problem here is if a penetrating object strikes your femoral artery, which runs the length of the femur in both legs. If this is nicked you’re facing an internal arterial bleed that is hidden under a pretty substantial chunk of muscle, so applying pressure may be difficult. Apply a tourniquet above the wound and get to a hospital ASAP. On the flipside, the average buttocks presents as a thick slab of fatty tissue under the skin, so a stab or slash will hurt due to the presence of several nerves (sciatic and inferior gluteal) , but bleeding out is less of a concern so long as the wound isn’t deep enough to pierce your inferior/superior gluteal arteries. (Stabbing in the ass is just plain rude and should be taken as a personal insult)
  • Lower Legs – Your shin and calf only house two medium-sized arteries, the anterior tibial artery on the front of the tibia bone, and the posterior tibial artery on the back. There are a few wrapped around you knee a well, but I’d be more concerned about slashing damage to the tendons in the area; as your ability to move, maybe even stand, will be hindered greatly.
  • Foot – So you got stabbed in the foot. My guess is you either dropped your still-armed opponent and they lashed out from the ground, it happens, or you tried to kick the knife out of their hand (Sorry, but you’re NOT Bruce Lee!) The anatomy of your foot is similar to that of your hands; the middle of the foot is densely packed with tarsal bones and the toes are longer metatarsal bones with gaps between them. The arteries here are generally smaller, the dorsalis pedis artery being the largest one, conveniently situated on the top of the foot, so you are unlikely to bleed out from a foot injury. Though any bleeding wound will be lethal if left unattended for too long, especially if you ability to run/walk is impeded.

So What?

I’m not sure how I could make it any more obvious that the location of any sharp force trauma you experience is a key factor in your survival as well as the severity of any lasting effects. Now that you know the vital targets, you are wise enough to buy both of these sets of personal stab/slash resistant armour and combine them for maximum coverage. As an alternative to uncomfortable daily wear, get trained and stay trained. Even the most basic knife-defence training will give you a chance of denying an attacker access to the worst strike locations, so you won’t have to worry (as much) about the above aftereffects of a knife breaking/entering into your body.

Beyond training for the refusal of physical attacks with a knife, large shard of mirror, #3 Robertson head non-slip screwdriver, etc., it would serve you will to practice the first two stages of self-defence; Avoidance and De-escalation. These two skills will, in most cases, keep the blood-seeking object far away from your soft, puncturable bits.

Written by: Corey O. – UTKM Yellow Belt

For training online visit www.utkmu.com. If you are in the Metro Vancouver area, come learn with us in person, sign up at www.urbantacticskm.com