Hontaibu No Atemi Waza

The word “Hontaibu” means body part. So, Hontaibu No Atemi Waza refers to techniques that target specific parts of the body. Each part of the body is affected in a different way by strikes, and of course different strikes can affect a given part of the body in different ways.

This section discusses various areas of the body that are vulnerable to attack from one or more different types of strikes. We will touch on numerous parts of the body, but we cannot possibly cover every strike and body combination. You are therefore encouraged to take it upon yourself to explore how different strikes may affect other areas of the body.


Some of the discussions may involve possible permanent injury, disfigurement or even death for an opponent. We do not suggest you seek these outcomes unless the threat to yourself or another would warrant such actions. We do not encourage nor support the random use of injurious activities against anyone, including a belligerent or aggressive attacker who could reasonably be subdued by other means.

In most of the strikes defined below we will discuss not only how to perform the strike, but the potential outcomes of the strike. This is important for two reasons. Firstly, if you strike an opponent in a manner that may be life-threatening it is incumbent upon you to seek assistance for them. For security reasons you may not wish to stay nearby, but you should nonetheless find a way to get the person any assistance they may require. Secondly, if you are yourself struck in some of the following locations you may need to pay attention to subsequent symptoms so that you may seek appropriate medical advice and intervention as required. This might save your life.


The kidneys (there is normally one on each side of the body) are located toward the back of the abdomen and are frequently thought of as being positioned in the small of the back, at either side of the spine and several inches above the hip. They are covered by thick back muscles that help protect them from impact. The twelfth rib largely covers the kidneys in the back, but the lower part of the kidneys are typically exposed below this rib. This all makes the kidneys a very hard target to strike, but when impacted they produce a tremendous amount of pain.

A strike such as a Ken Tsuki that penetrates sufficiently into the lower back to strike a kidney will likely result in a dramatic surge of pain for an opponent. If struck with sufficient force the person receiving the strike may well fall to their knees in extreme agony. This is an extremely painful injury, and one that could be life threatening.

Injury to the kidneys is classified using five grades that range from simple bruising through complete destruction (as might be experienced with a gunshot wound). Each of these injuries would be quite painful (at least initially). Injuries resulting from a martial arts strike are likely to result in simple bruising, but more severe damage to the kidney (such as rupture or detachment of the organ) could result. Internal hemorrhage and/or urine leakage could occur following such an injury. It is possible that hemorrhage or infection could result several days after an injury. If the injury is relatively severe then the injured party may detect blood in their urine. However, there may be blood in the urine even if it is not readily visible. Only microscopic or chemical testing can rule out the possibility of blood in the urine. People who suffer a blow to the kidneys should always seek medical treatment and appropriate monitoring to ensure they do not have any lasting complications.

A possible side-effect of a kidney injury is elevated blood-pressure. If the kidneys are not able to sufficiently remove excess fluids then blood pressure levels will likely increase. This is of reduced concern if a person has both kidneys, but would still be something that should be appropriately monitored by a medical professional.

If an individual has only a single kidney then a kidney strike could put them at significant risk, especially if the kidney suffers a rupture. A person with a compromised cardio vascular system could also be put at significant risk several days after a kidney strike if their blood pressure levels rise significantly.

So a strike to the kidneys should not be considered a benign strike. It is difficult to access the kidneys because of the protective layers afforded by the lower back, but if struck the resulting pain is usually quite severe and lasts for several minutes at least. You would typically not strike to the kidneys because they are difficult to impact significantly and, if struck, can cause significant medical complications for the strike recipient. Naturally, if your life is in danger then this could be an effective strike that might well result in an immediate cessation of hostilities. Just plan to use other strikes or movements as well in the likely event that this strike does little or nothing to the opponent.

A strike such as an Ippon Ken Tsuki is more likely to affect the kidney of a standing individual than a strike with a larger surface area, such as a Ken Tsuki. The small surface area of a single knuckle is more likely to penetrate through the muscle tissues and therefore is much more likely to deliver sufficient focused energy into the kidney. However, impact by the ball of the foot from a Mawashi Geri may have enough force to cause deep tissue injuries that could affect a kidney.

Similarly, if an individual is bent forward then a strike such as a Tate Tettsui Uchi or Tate Ken Tsuki could easily cause kidney injury. If you are standing near the waist of an individual then the Tettsui Uchi may best be focused on the farthest kidney so that the arm has proper structure and orientation. This is a general anatomical and distance issue. The nearest kidney is not always the easiest to reach and may be protected by underlying anatomical structures such as muscles, ribs, and the spine. The angle of attack may also not be beneficial and could preclude a forceful strike. Selecting the appropriate target and striking methodology would depend, in part, on all of these factors.

Celiac Plexus

The Celiac Plexus, also commonly known as the Solar Plexus is an area that many martial artists consider to be a prime target. A plexus is an area containing a substantial cluster of nerves and the celiac plexus certainly qualifies in this regard. It is the largest plexus in the autonomous nervous system. It is commonly thought that striking to this area of the body will cause the diaphragm muscle to go into spasm, causing pain and an inability to breathe for a short period of time (perhaps up to a minute or so). The common phrase for this phenomenon is “having the wind knocked out of you.” In reality, the diaphragm is temporarily paralyzed by the inability of the disrupted nervous system to send it organized signals.

While a strike to this area can cause the aforementioned results, things are seldom that easy. The celiac plexus is actually buried pretty deeply in the body. It is behind the abdominal muscle wall and then the stomach and just below the diaphragm. This can make striking this nerve-center somewhat difficult, especially if the person is in good physical condition, has strong abdominal muscles, and is aware of how to flex these muscles to protect themselves from a strike. My experience has been that people who are trained martial artists seldom experience this problem because they typically have all three of these attributes.

The nerves in the celiac plexus support intestinal contractions, breathing and adrenaline release controlled by the autonomous nervous system. It is an extremely important nerve center and is vital to life. Striking to the area of the stomach may cause breathing difficulties as previously discussed. This can cause panic in an individual as they struggle, for a short time, to breathe. Because this is a nerve-rich area of the body it can also be a painful experience, but it is much more frightening than it is painful. If your strike elicits this response then it will afford you ample time to escape or summon assistance.

This area of the body also contains many vital organs, including large portions of the digestive tract, liver, and pancreas. All or significant portions of these organs are not protected behind the ribs. As a result they are vulnerable to attack from a strike to this region of the body. Striking in this region may cause other injuries. It is quite common for people to suffer bruises to the ribs, organs and sternum from such a strike. In some cases cracked or broken ribs may result. These are injuries that may yield a prolonged period (weeks) of pain.  Organ damage and/or internal bleeding are possible outcomes of strikes to this region of the body.

When you inhale the diaphragm extends downward slightly below the rib cage and presses somewhat into the abdomen. When the diaphragm contracts it pulls back up so it is fully protected behind the ribs. Since the celiac plexus is in front of the diaphragm the movement of the diaphragm causes both a harder surface and a void behind the celiac plexus during a normal breathing cycle. Having a void (it is not actually a void since other less-muscular tissues move into the area) behind the celiac plexus allows a deeper penetration of a strike in this region. Without a void then the celiac plexus is compressed between the abdomen wall and the diaphragm. Both can have benefits for such a strike.

Perhaps the most effective hand strike to this area is either an Ippon Ken Tsuki, Oyayubi Ippon Ken Tsuki, or the 45° angled punch which fits nicely between and below the two sides of the rib cage. Effective kicks to this area are the Mae Geri and Mawashi Geri. In both cases the strike is most effective if the ball of the foot or toe of a shoe is used as the striking surface.

Your best defense against this type of attack is strong abdominal muscles, the ability to quickly rotate your center away from such a strike, the ability to preposition or move quickly out of way of such an attack, and practice clenching your abdominal muscles just before the moment of impact. You are in severe jeopardy if you are impacted in such a way that your diaphragm goes into involuntary contractions.


Striking to the throat generally involves directly impacting the Trachea, often in the vicinity of the Larynx. Strikes may be impeded by a lowered chin or by a well-positioned guard, making this area sometimes difficult to strike. The following strikes can be used to readily slip into the perhaps reduced space between the chin and the clavicle.

All of these strikes are delivered with a relatively flat hand structure making them fairly easy to insert under a descended chin.

If the chin is raised or the head tilted backward then other more powerful strikes might be used. Most of these strikes are impact strikes that may cause crushing injury to this part of the body. An exception is the U-Hand Strike that may be inserted such that the thumb and fingers strike just wide of and on opposing sides of the trachea. Squeezing the fingers and thumb together and pulling abruptly will have a tearing and pulling effect on the trachea, causing a different form of injury.

The most obvious problem that striking to this area can cause is the inability to breath. Even if the strike is not sufficient to cause permanent damage a person struck in the trachea may experience spasms, coughing episodes, and a general sense of respiratory distress. These problems can be quite sever if the trachea is physically damaged. Such distress can lead to impending death if the result of the strike is a blocked airway. This can be a serious and immediate life threatening condition. Sufficient panic could lead to cardiac arrest or other unintended consequences.

As with any life-threatening injury this should be avoided unless you feel it is the only remedy to protect yourself or others. This is a very effective target area and will likely cause your opponent to stop an attack, but it may be at the risk of their life. Avoid these types of strikes unless they are essential to your survival.

You must protect yourself from such a strike in a conflict. Move out of the way, turn your center away, maintain an effective guard, keep your chin down slightly, block such strikes, or learn to keep your opponent sufficiently off structure and disoriented so they cannot deliver a strike to your throat.

Carotid Artery Sinus

As discussed later in this manual in the section covering the circulatory system, the carotid artery sinus is critically important for maintaining proper blood pressure in the body. This is a small pressure-sensitive area in the arteries supplying much of the blood to the brain. The baroreceptors in the carotid sinus detect and communicate blood pressure changes to the brain. This is part of the feedback mechanism the body uses to regulate blood pressure.

Since the baroreceptors are very sensitive to pressure changes, applying pressure to them directly can send false signals to the brain. This is sometimes done as a medical massage technique to directly affect blood pressure. It is not something you should attempt yourself.

The carotid sinuses are located on either side of the neck in the soft tissue area between the trachea and the thick muscles toward the back of the neck. They are a little above midway between the shoulders and the mandible and very near the surface.  This makes them readily accessible to a strike or direct manipulation.

A strike such as a Shuto Uchi that lands directly on a carotid sinus can have instantaneous results. This typically makes the brain sense that the body has undergone a tremendously rapid increase in blood pressure levels. It compensates by reducing the heart output immediately, which in fact suddenly lowers blood pressure levels throughout the body. The person who was struck may immediately collapse into unconsciousness.

In most cases the person will soon recover consciousness without any lasting effects, but in some cases, especially in someone with significant health issues, the heart may stop completely, leading to death if immediate assistance is not provided. Another serious injury may also result. If the associated arteries are in any way torn or severed then the injured individual may quickly die. This clearly means this is a potential immediately lethal strike and should be utilized only in the most ominous circumstances.

This can be a difficult strike to land precisely due to the curvature of the neck, the location of the carotid sinus, the relative heights of you and your opponent, the physical condition of your opponent, and numerous other factors. There is no guarantee a strike to this area will render an opponent unconscious – in fact the odds are dramatically against this outcome. I do not have any statistical data to indicate the likelihood of such a strike rendering someone unconscious, but I can say I only know of a very few cases where this has occurred. Nonetheless, a strike to this area of the body will likely cause significant pain.

Pressure can be applied to these sinus areas using other methods as well. An arm bar (such as a Naked Rear Choke) might be used to press into these sinuses to again send false pressure signals to the brain. Holds like these also usually have the effect of restricting blood flow to the brain which normally leads to a loss of consciousness in under ten seconds. If someone is rendered unconscious in this manner the pressure on the neck must be immediately released or severe brain damage or death could result.

It may be possible to strike to the carotid sinuses using other strikes when you are positioned on the ear side of your opponent. Here strikes such as the Ippon Nukite Uchi, Ippon Ken Tsuki, or Tate Hiraken Tsuki could be used to impact this target. Even a Web Hand could be used to encircle the throat and apply pressure to one or both of these carotid sinuses. The Web Hand is a bit more tenuous since it may be readily dislodged by the opponent before it has sufficient time to cause significant effect.


Everyone thinks of striking to the groin. It is by far the most frequent target area envisioned by someone thinking about self-defense maneuvers. It is, however, a fairly hard target to strike. This is largely because, given sufficient time, it is easy for someone to step back, rotate the pelvis, pull back the hips, or raise a leg in defense, or potentially even block such a strike. Also the large muscles in the legs and abdomen can deflect or interrupt a strike that is even slightly off target.

In a male a successful strike to the groin can be quite painful, or it can have little or no effect whatsoever. If pain is the result then the person is likely to collapse to the ground and to curl up in the fetal position as they writhe in temporary agony, rage, and discomfort. The immediate pain subsides after a few moments only to be replaced by equally distressing general lower abdominal pain, weakness, nausea, and breathing distress. It is a very intense, long-lasting, and powerful reaction to what might have been a fairly limited or even glancing initial strike.

On the other hand, a person may not be affected in any way at all. This can be the case if the person has undergone extensive sensitivity training against strikes to the groin. Some individuals have done this and can take a direct and unprotected full force strike to the groin without any apparent side effects of any kind. These are rare individuals usually with substantial martial arts training and they are probably not the person who is attacking you.

Another class of individual who may not be affected by a strike to the groin is someone who is heavily under the influence of alcohol or drugs. This slows down or inhibits nerve transmissions and may make them completely oblivious to normal pain.

And of course clothing, musculature, or bad aim could cause a strike to be ineffective. Quite often a strike to the groin will strike the inner thigh which absorbs most or all of the strike energy.

As a result you cannot rely on a strike to the groin as a final strike. There are too many variables. You must ensure, as in any strike that this is not thought of as your last strike. You should roll immediately into your next movement as though this one had no effect. If your opponent collapses to the ground, then move away. Otherwise, keep going until you can effect an escape or can otherwise render the opponent incapable of continuing.

The most common strike to the groin is a Kin Geri. It works quite well whether delivered from the front or rear of the opponent. Because this can be a very forceful strike it might also lead to pelvic area bruising and perhaps to a pelvic bone fracture. It may also lead to permanent reproductive organ injury.

A hand strike such as a Sword Hand or Haito Uchi can also be a very effective groin strike if you have access directly along the opponent’s center line. These strikes might be applied in a straight line outward-descending manner, or could be applied such that they are positioned initially below and then rise upward into the groin. You should practice these strikes in both ways so that you have either option available to you.

If you are down on one or both knees then a Kakuto Uchi or forearm strike might be employed. The latter is most effective if it is combined with a subsequent hand grab and pulling maneuver that might directly attack and rip at the testicles in males.

There is a misconception that females are not susceptible to groin strikes. Females can be just as significantly impacted due to the nerve-rich environment and therefore tremendous pain that can result from such a strike. Female pubic bones are also generally less massive than the same bones in males, making females more likely to suffer a break to this bone.

In nearly any martial arts competition you encounter you will find that strikes to the groin are completely prohibited. You will also find that anyone participating in such tournaments is wearing full groin protection to protect themselves against an errant or intentional strike to the groin.

You should keep in mind that the martial arts is a contact sport. You should therefore always wear a groin protection device of some sort when participating in even the most innocuous of training activities. People have other things to do besides spend fifteen minutes sitting around while you recover from an accidental strike to the groin.

Thigh Muscles

The upper thigh has roughly a dozen different muscles that are involved in controlling the leg. These are large muscles that can be easily bruised by a strike of sufficient focus and intensity.

For example, if someone delivers a Mae Geri in your direction, then stepping to the face side or ear side as you deliver a Tate Tettsui Uchi down into the mid-thigh is likely to cause immediate tissue damage. This may make it more difficult for the person to then use this leg as effectively.

In a similar way a Ken Tsuki could be applied into the side of the thigh to damage the muscles in this area. Either the inside or outside of the thigh could be targeted with generally equal effect.

In both of these scenarios you would need to ensure that you are not using your hand or arm to absorb the impact of the kicking leg. You would want to time your strike so that it impacts the leg when the leg would not deliver its own striking force into your arm or hand.

If your opponent is standing and you are in close proximity then using your knee to strike into the thigh can cause a fairly massive bruise to the opponent’s leg. Such a strike could be delivered to the front, sides, or back of the thigh.

The most damaging strikes to the thigh however come from kicks. The Mawashi Geri, Yoko Kekomi Geri, and even the Mae Geri can cause massive bruising to the thigh. These are primary striking methodologies in styles such as Muay Thai that focus, in part, on punishing an opponent’s body with repetitive powerful kicks.


Striking to the forearm can, if properly applied, render an opponent’s hand and lower arm ineffective for some period of time.

The radial nerve winds its way down the arm and eventually all the way to the hand. The nerve and its major branches are often under a substantial covering of muscle. A superficial branch of this nerve travels from the outside of the lower arm near the elbow, then works its way, over the length of the forearm, across the top of the arm until it reaches the hand near the thumb.

Striking the arm directly over top of this part of the radial nerve in the forearm can cause immediate pain and loss of function in the forearm and much of the hand. The nerve is used to control extension of the wrist, movement in much of the hand, and for feeling in the back of the hand, thumb and first two fingers. Striking the radial nerve can cause loss of control of the wrist and part of the hand and severe tingling in the hand.

Striking the top of the forearm with a strike such as a Tettsui Uchi may not only impact the radial nerve but may bruise and temporarily impair use of the muscles in the arm. This is often used as part of a disarmament maneuver if someone has a weapon, though there are better ways to remove a weapon from an opponent’s grip should you ever find yourself in such an unfortunate situation..


Ribs are numbered 1 through 12, beginning with the rib nearest your shoulder and descending downward. There are twelve ribs on each side of your body that generally go from the sternum to the spinal column. The first seven ribs on each side connect at the front, via the costal cartilage, directly to the sternum. In the back they connect via cartilage to the spinal column.

The first seven ribs connect directly to the sternum via cartilage. These are commonly referred to as the true ribs. The next remaining five ribs are referred to as the false ribs. The first three false ribs (ribs 8, 9, and 10) connect to the cartilage of the 7th rib rather than to the sternum directly. The last two ribs are called floating ribs and have no connection to the sternum at all. These ribs generally protect the lower back. All ribs connect to the spinal column.

The Intercostal Space is the space between any two adjacent ribs. Intercostal spaces are numbered as well, beginning with the space immediately below the first rib (technically between the first and second rib). This is intercostal space number one. The numbers for intercostal spaces increase as you move downward toward the abdomen. For example, the intercostal space between the fifth and sixth ribs is intercostal space five.

This general area of the human anatomy is heavily muscled. There are far more muscles here than you might first imagine. Along the back the very large latissimus dorsi muscles are the outermost layer of muscles. In the front are the pectoralis major muscles covering the upper ribs. The lower frontal ribs are covered by the rectus abdominis muscles. On the sides the serratus anterior muscles form the outer and most visible layer of muscles. Inside of the serratus anterior muscles are the external abdominal oblique muscles. Finally we come to the intercostal muscles.

There are three sets of intercostal muscles that are attached directly to and between the ribs. These are the external intercostal muscles, the internal intercostal muscles, and the innermost intercostal muscles.

The outward-most muscles in this group are the external intercostal muscles. These muscles are attached near the outside bottom and top of two adjacent ribs. These muscles function to lift and expand the ribs during inhalation to facilitate the respiratory process.

The inner intercostal muscles sit inward of the external intercostal muscles and again attach to the bottom and top of two adjacent ribs. These muscles help contract and lower the ribs during exhalation.

The innermost intercostal muscles attached to the inside bottom and top of two adjacent ribs. They are an aid in contracting the chest during exhalation and especially useful during periods of forced exhalation.

Between the external intercostal muscles and the internal intercostal muscles runs a nerve and blood vessel bundle containing a vein, an artery, and a nerve that support the muscles in this area. This bundle lies just below the top rib within an intercostal space and these are stacked vertically in the order vein, artery, and nerve (VAN).

From all of this we can deduce a few things of interest, including:

  • The ribs can move relative to one another (vertically, if a person is standing)
  • The ribs are separated more during inhalation (or at peak inhalation)
  • The ribs are closest together after exhalation
  • There are a great many small muscles between any two ribs
  • There is a nerve present near the top of any intercostal space
  • There are frequently larger muscles that overlay the ribs

Rib injuries are extremely painful and do not heal quickly. They are often extremely painful during the entire course of the healing process, so these injuries do not start to feel even marginally better until they are almost completely healed. Cracked, bruised, or broken ribs take a very long time to heal and are intensely painful. If someone makes you laugh the resulting pain will make you a most unpleasant person.

The intercostal muscles generate a similar level of pain if they are injured. Bruising or tearing injuries to these muscles cause a great deal of pain and take on the order of six weeks to heal. A sudden twisting motion or an unexpected fall can cause you to pull one of these muscles. The results will be weeks of pain in a very specific area in your chest wall.

The side ribs, just forward of the serratus anterior muscles have limited muscle covering and are therefore a common place to attack when attempting to strike to the ribs. A focused strike such as a Tate Ken Tsuki or a Shotei Uchi that impacts directly on top of a rib may cause bruising or more extreme injury to a rib bone itself. A more focused strike such as a Nakadaka Ippon Ken Tsuki, Ippon Ken Tsuki, Shuto Uchi, or even a Nukite Uchi that impacts in an intercostal space may inflict injury on the intercostal muscles, particularly the external intercostal muscles. With sufficient penetration it may also compress or irritate the associated nerve, causing additional pain.

When striking to the ribs it is often beneficial if you can either strike when an opponent has inhaled, when the overlying muscles are relaxed, or when one side of the chest has been expanded by causing a person to lean toward their opposite side.

Kicks are quite effective for causing blunt force injuries to the ribs. A Mawashi Geri can deliver a very forceful blow against the side, back, or front ribs (depending on the opponent’s relative position). A kick such as a Yoko Kekomi Geri is especially useful for causing bruising and possible damage to the ribs. But even this kick is unlikely to cause a massive injury since the ribs are generally very strong and well protected. Nonetheless, there are numerous vital organs beneath and near the ribs that can be damaged with sufficient force. Even if these strikes do not hit a vital organ they may cause weeks of intense pain.

This is why it is essential that you keep a good frontal guard and ensure that your elbows are down to prevent a Mawashi Geri from getting up under the arm and into your ribs. Kamaete!

An injury to the ribs may not be apparent to the injured person for several hours or even until the next morning. This makes these strikes less than ideal for stopping an opponent immediately. However, if used as part of a continual striking pattern the cumulative pain and impacts can result in wearing down an opponent in a relatively short period of time. So, while striking to the ribs is unlikely to cause serious injury (but one never knows for sure) and will not likely put an abrupt end to hostilities, they can be an effective strike location as part of the effort to persuade an assailant that further conflict is not in their best interest.

You will learn more about the ribs and potential rib injuries in later belts.

Arm Pit

We’re about to expose some myths about striking to the armpit. Here are a few of the common misrepresentations you will find regarding striking to the armpit. Below each point is an explanation about why it is a myth.

  • There are copious nerves in this area and a strike to this nerve-center will cause extreme pain
    • There are no more nerves here than in other areas of the body
    • Because this area of the body is somewhat protected it may be a bit more sensitive to impacts, but not remarkably more painful than other areas of the body.
  • A strike here, if properly placed, will strike a sweat gland or lymph node and release deadly toxins into the body that will kill a person in three to five days
    • Sweat glands are on the skin and are located nearly everywhere on the body (except for a few limited and specific locations). The armpit and a few other limited locations have specialized sweat apocrine glands. Unlike regular eccrine sweat glands that emit primarily water and salts, the apocrine glands emit an oily fluid containing a mixture of water, salts, fats, pheromones, and trace minerals like copper and magnesium. While they do contain a few toxins (e.g. uric acid), they mainly contain sweat, fats, and pheromones. Striking a sweat glad (you would be unlikely to strike a single sweat gland) would release very few if any toxins into the surrounding tissues. Sweat is comprised mostly of water. Hitting a sweat gland will primarily release water.
    • There are lymph glands in the armpit and they collect foreign bodies and cancer cells, but they do not deal with or retain toxins. Striking a lymph node is therefore unlikely to release a deadly cascade of toxins into the body. Such a strike might release some foreign or cancerous cells, but in all likelihood the body will simply remove them again via another lymph node without any significant affects. Certainly nothing here will cause you to die in four days.
  • Striking to the proper location in the armpit will cause a person to bleed to death in a few hours
    • There are veins and arteries under the armpit that could cause significant bleeding or possibly death if ruptured. But these are fairly deep in the tissues and are unlikely to be ruptured by a strike to the area.
    • It would likely require a very sharp and pointed object to cause such a significant blood vessel rupture. There are other more deadly areas for such a strike if that were your intent.
    • The primary arteries, veins, and nerves that supply the arm go through the lower front shoulder and then enter at the top and front portion of the arm near the bicep muscle. These would not be accessible via a strike to the armpit.
  • A strike to the armpit will cause a person’s arm to go numb for several minutes
    • There are a few nerves within the armpit that aid sensitivity and movement of muscles in the side, ribs, and portions of the back. None of these nerves is likely to affect the arm.
    • Nerves that would affect the arm itself come via the front of the shoulder and enter the arm forward of the armpit. If the arm is raised these nerves might be targeted, but such a strike would be forward of the armpit and at the point where the shoulder and upper arm meet.

All of the above major bullet items are essentially myths. None has any significant basis in truth and are examples of the types of half-truths, ignorance, and complete misrepresentations that occur within the martial arts community. You must remain suspicious of any claims that are not borne out by scientific, anatomical, and demonstrable knowledge. Here are some things that are true about the armpit.

The armpit is a somewhat protected area of the body and therefore does not frequently suffer impacts. It is perhaps a bit more sensitive to impacts that other areas of the body (for example, the arms). But it is hardly “super sensitive.”

A strike such as a Nakadaka Ippon Ken Tsuki will penetrate more deeply into the tissues of the armpit and may cause associated pain, bruising, and discomfort. This is no different than any other area of the body.

It is actually quite difficult to strike someone in the armpit. While it is not impossible to strike to this area of the body, it is fairly unusual. Your timing and prior movements would need to be perfect to enable such a strike to occur. The opponent’s arm must be raised and they must be turned, relative to yourself, in such a way that a strike along your center line will penetrate directly into the armpit. It is not impossible, but it does require a bit or orchestration.

There are arteries and veins in the area that, if disrupted, could cause substantial bleeding. While any internal bleeding is bad, it is not clear this would be sufficient to cause impending death. You would need to penetrate very deeply and with substantial force to cause such an injury. This is an unlikely result from a hand strike, but in a dynamic situation anything is possible. But you would be ill-advised to think of this as a likely outcome of such a strike.

Grabbing the muscles toward the front or back of the armpit and squeezing or pinching firmly is likely to cause more temporary pain than will a full-fledged strike. Similarly, if the person has exposed hair in the armpit then pulling the hair with a quick jerk will likely be quite painful. You’ll want to remove your hand quickly to avoid their immediate elbow-down reflex reaction in either case. Failure to remove your hand could result in your hand being trapped under the opponent’s arm. That would be less than advantageous.

So in Tensoku Ryu we consider the armpit to be useful as an area for pain compliance. We would utilize the sensitive nerves in the skin rather than underlying nerves to cause sufficient pain to induce a specific movement or reaction from an opponent. But this is not an area in which you will be able to sustain the application of a painful action. This is pretty much a “cause some pain and move on” area of the body. It does not have any magical or mystical qualities (that is, strictly speaking not entirely true, but any such mystical qualities have absolutely nothing to do with pain, death, or injury).


Striking to the temple area is often cited as an effective way to knock someone out and to quickly put an end to a conflict. The general consensus seems to be that this causes the brain to be suddenly compressed on this side of the skull as the head lurches away from the impact of the strike. Since the brain is relatively free-floating in the cranium, it does not necessarily move as quickly as the head (remember inertia?), therefore causing the skull to crash into the brain before the brain can begin to move. The brain is then subsequently forced away from the direction of impact, only to impact the skull on the opposite site of the head. These are referred to as coup and countercoup injuries and frequently lead to bruising or bleeding of the brain in these areas. This requires a quick and sudden jarring impact, the kind of thing that might result from a roundhouse type punch or kick.

The most likely strikes to impact the temple area are a Mawashi Geri, Mawashi Tsuki, Tettsui Uchi, Uraken Tsuki, or Ura Mawashi Geri. Each of these strikes has the ability to penetrate behind and around an individual’s guard and to strike the side of the head in the vicinity of the temple. Each results in a sudden and jarring impact to the head. If you move to the ear side of your opponent then other strikes such as Ken Tsuki will also cause similar impacts.

The result of such an impact is that the brain has suffered trauma. This may cause an immediate and confusing mix of nerve messages that may affect autonomic nerve functions and may cause a sudden loss of consciousness. Consequently the person may have been “knocked out.” Unfortunately, this may not be an innocuous injury.

The area of the skull just behind and above the temple is called the pterion. It is the junction of four different skull bones (the frontal, parietal, temporal, and sphenoid bones). It also happens to be the thinnest bone area in the entire skull. This makes it susceptible to fracture in the event of a nearby impact (or even if an impact elsewhere in the skull that causes this area to be placed under compressive stress). The pterion can be fractured even with relatively light impact forces. A fracture almost always causes any dislodged bone to press inward into the head.

The large middle meningeal artery runs just inside the skull and under the pterion. A fracture here may rupture or even sever this artery. Both conditions are very dangerous as they cause blood to leak into the area between the skull and the brain. As sufficient blood accumulates it will tear tissues away from the skull and increase pressures on the brain, which precludes normal blood flow within this area of the brain. The brain in this area can subsequently die, potentially leading to severe disabilities or death for the individual. Pretty gruesome stuff.

Striking directly to the temple does not guarantee that the person will lose consciousness. Boxers are struck here all the time and seldom are knocked out after a single blow. They may continue to fight as though they were not affected. If the pterion has been fractured however, they may later have very severe effects that could be life threatening.

The problem with this injury is that it may take some time for enough blood to accumulate before there are noticeable symptoms. If you have been struck in this manner you will want to be vigilant about detecting any of the following symptoms (these may not be the only symptoms):

  • Loss of Memory
  • Severe Headaches
  • A desire to sleep at odd times or soon after being struck
  • Dizziness or disorientation
  • Vomiting
  • Dilated pupil
  • Extremities weakness
  • Slurring of speech
  • Respiratory irregularities
  • Loss of consciousness (even temporary)

If any one of these symptoms or any other irregular behavior or symptom occurs after a strike to the head then this may be a very serious and life-threatening event. Immediate medical evaluation is essential or you may well die. This is a problem that will not go away and you may only have hours to live.

There are a few things to take away from this discussion.

  1. Striking to this area of the head may cause a whiplash type motion that results in unconsciousness, even if the pterion is not fractured.
  2. There are no guarantees that loss of consciousness will result from such a blow; in fact the odds are against it.
  3. If the pterion is fractured then very serious and life-threatening consequences may result. This can result from even a relatively minor strike to this area of the head.
  4. If you have been struck in this area of the head you must be very vigilant about monitoring for and detecting abnormal symptoms that might be attributed to this type of injury. It is likely prudent to seek medical evaluation even if you do not exhibit any obvious or definitive symptoms.
  5. It is essential that you keep your guard up at all times to prevent these types of injury.
  6. All Tensoku Ryu practitioners must wear protective head gear and hand protection when performing Kumite or free sparring to reduce the possibility of such injuries. The head gear must provide abundant protection for the temple area of the head. There can be no exceptions – we like our students.
  7. In Tensoku Ryu we never deliberately strike to the temple area unless we intend to cause serious and perhaps fatal injuries to an individual. Since these injuries may not manifest themselves for many hours it is difficult to justify that these strikes helped put an immediate end to a conflict. Therefore we do not favor this type of attack as a self-defense methodology.
  8. When sparring, this area of the head is off limits. In Kumite this is often a target area to “show” a strike, but these strikes should never land on the head and are instead pulled short in a show of control and precision.

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