Friday, July 6, 2012

A Neurophysiological Approach to Kyusho (急所)

I first started looking into the neurology and physiology related to kyusho(1) around 1985. By around 1993 I had formulated a rough outline of what I felt might serve as (the beginnings of) a neurophysiological approach to kyusho.

These are the topics I believe may provide the best neurophysiological explanation for the effect of kyusho strikes. I've divided them into three general categories


1) Adrenaline and hyperreflexia
  • One often hears that vital points will be less useful “on the street” than they seem to be in the dojo because adrenaline will supposedly dull the effects of vital point techniques. Everyone knows that there is a decreased awareness of injuries sustained in adrenaline fueled combat. Talk to nearly any soldier and they can probably give you an example of somebody they know that didn’t realize they were injured (or at least didn’t realize how badly they were injured) until after the high levels of adrenaline in their blood had substantially decreased. These stories are true and I can even offer a few examples of my own. However, a critical fact is often ignored in these accounts: adrenaline did not in any way decrease the injury, it just decreased the awareness of the injury.

    When I was about seventeen years old a friend and I got into an altercation with six other boys (two of whom did little more than watch and offer encouragement for their friends). I had kicked off the flip-flops I was wearing to make sure I had good footing. After the altercation was over my friend asked “how bad is your foot?” I had no idea what he was talking about. I looked down and saw that my left foot was bloody, and upon inspection I saw that I must have stepped on a piece of glass during that altercation. My friend had noticed that I had a very pronounced limp as I was walking towards him. The adrenaline had made me unaware of the injury. It did not prevent the injury nor did it stop my body from reflexively responding to the injury (causing the limp my friend noticed).

    What this means in practical terms is that *pain compliance* is less useful under the influence of adrenaline. People who don’t understand Okinawan Kyusho-jutsu and Tuidi often interpret this as meaning vital points and joint locks are useless (or at least less useful). However, what these people fail to understand is that Kyusho and Tuidi techniques are NOT aimed at causing "pain compliance". Kyusho and Tuidi techniques are aimed at causing injury, dysfunction, or reflexive reactions that can be exploited to the defender's distinct advantage. While pain may be a typical result of these techniques, it is never the purpose of these techniques. Pain is merely an ancillary side-effect. So the entire issue of "pain compliance" is completely irrelevant.

    People sometimes claim that adrenaline supposedly dulls reflex reactions. However, scientific research indicates this is definitely NOT true. In fact, adrenaline results in an amplification of reflexes. This state of amplified reflexes is called hyperreflexia and adrenaline is *by far* the most common cause of this state. Adrenaline amplifies neuromuscular reflexes such as myotatic reflexes, withdrawal reflexes, and autogenic inhibition reflexes. In other words, adrenaline makes the most fundamental level of Kyusho-jutsu even more effective.

    *More effective*, not less effective.

    Given the effects of adrenaline on blood pressure, one might assume it makes blood-pressure related knock outs (hereafter referred to as “BP KOs” or “syncope”) less likely.

    Scientific studies like _Effect of adrenaline on vagus nerve reflexes_ (by Masaki, Furukawa, Watanabe, & Ichikawa) have found that adrenaline does dull the blood pressure lowering effects of vagal stimulation in many parts of the body but it actually *amplifies* the sudden decrease of cerebral blood flow. In other words, adrenaline makes BP KOs far *more* likely.  Strikes stimulating the vagus nerve, the three main branches of the trigeminal nerve, or  barroreceptors located in the neck and chest, are significantly more likely to cause unconsciousness if the attacker has an elevated adrenaline level.

    To the best of my knowledge there has been no direct research on the effects of adrenaline on cutaneovisceral reflexes (although existing research has found that some noxious stimuli, which can certainly be expected to elevate adrenaline levels, do reliably trigger these reflexes). However, given that adrenaline amplifies the effects of Kyusho-jutsu’s neuromuscular reflexes and BP KOs it seems probable that the effect of Kyusho on the internal organs either remains the same, or is amplified, under the influence of adrenaline.
2) The use noxious stimuli to trigger the flexor reflex as well as closely related ipsilateral and contralateral reflex actions.

3) Mechanical compression of a nerve leading to paresthesia, transient muscular dysfunction and/or neurapraxia.

4) Deep tendon reflexes (myotatic reflexes) and muscle spindle stretch receptors

5) The autogenic inhibition reflex

Knockout and Syncope

Here is a perfect example of a very typical kyusho-jutsu knock-out (a forearm blow to the side of the neck), complete with pretty good tai-sabaki, being performed in an actual (real life) self-defense situation:

6) The 5 main baroreceptors of the body and their relative potential for producing vasodilation etc.

7) Trigeminal nerve and the vasovagal response

8) Neurocardiogenic syncope triggered by trauma (sometimes even just the anticipation of trauma).

9) Enhanced or disguised "boxer's KOs"

  • Linear impact KOs
  • Sudden rotational head motion KOs
  • Using the arm to cause a sudden rotational head motion KO
  • Using nerve impact to enhance a "Boxer's KO" 

Vital points and Viscera

10) Cutaneovisceral reflexes and the myodermatomes

11) Referred pain locations as well as the viscero-cutaneous reflex

12) The relationship between 10 and 11 and the Shu and Mu points of acupuncture

As time goes by, I'll be slowly adding descriptions of how I believe these topics are related to kyusho effects. In the meantime I hope this list provides readers with potentially fruitful areas of research.


Although modern Western medicine (particularly neurophysiology) almost certainly offers the best explanations for the effects of kyusho techniques, many Chinese, Japanese, and Okinawan martial arts still use the pre-modern conceptual framework of traditional Chinese medicine [医学] to teach vital point techniques and revival methods.

This can be seen in these videos of kyusho and kautsu techniques being taught in the traditional fashion in the art of Shorin-Ji Kempo:

(1) The art  of attacking vital points is refered to by numerous names. In karate it is usually called Kyusho-jutsu [急所術]  or Tsubo-te [壺手] ("chibudi" [チブディ] in Uchinaguchi). Other terms include Tenketsu [ 點穴] ("Dian Xue" in Mandarin or "Dim Yut" in Cantonese) and Tenmyaku [點脈] (“Dian Mai” in Mandarin or “Dim Mak” in Cantonese).


  1. ...hello,
    how nobody used some of these in combat sports like those Mixed martial ones?

    1. People occasionally ask the question “if they are so effective, why aren’t kyusho used in MMA?” This is a lot like asking “if it is so inexpensive, why don’t people shop at Walmart?”…

      The answer is that people DO shop at Walmart, and kyusho IS used in MMA. The word kyusho refers to anatomically or physiologically weak areas of the body. Don't be confused by the Bulshido sometimes CALLED kyusho. Okinawan kyusho-jutsu is very practically minded. Anyone doing bare-knuckle full-contact karate or MMA should be aiming at weak areas of the body (which means they are attacking kyusho).

      Many of the KOs seen in full contact karate are blows to the carotid sinus or trigeminal nerve (especially round-house kicks to the neck or behind the ear) and the majority of KOs in MMA are boxer's KOs, many of which land on a branch of the trigeminal nerve (and thus probably qualify as what I call an “enhanced boxer’s KO”). For instance, the best known and most commonly used of the “knock out kyusho points” is the mental foramen (sometimes called "the button" in boxing because it turns you off like a switch).

      Deep tendon reflexes and flexor reflexes play a significant role in grappling/joint-locking.

      The vasovagal response is almost certainly primarily responsible for loss of consciousness in so-called "fast chokes".

      Those leg kicks that cause a nice little limp are typically either the autogenic inhibition reflex or mechanical compression of a nerve leading to transient muscular dysfunction. Compare the effectiveness of leg kicks in the UFC to their effectiveness in "Bully Beatdown" to get a good picture of how much more effective this stuff is on fairly tough guys who *AREN'T* world class fighters/athletes.

      The fact that this stuff works on toughened, well-conditioned, world class athletes (who tend to be far less susceptible to effects from rapid fluctuations of blood pressure) as much as it does only goes to show how effective it will be on the average guy.

      Like I said, this stuff gets used all the time. Sometimes people call it kyusho, but more often they use colloquialisms like "dead leg" or "got his bell rung" or KTFO.

      But as to why they are not seen *even more often* than they are, the primary reasons are that many competitors don't have a detailed knowledge of the topic, and probably just as important, the range these events start at doesn't favor pin point accuracy.

      Kyusho works best in the very beginning of real-life encounters which typically begin at very close rage allowing this type of technique to be used with greater confidence.

      The video posted above is a perfect example of a real-life application of kyusho-jutsu. As you can see it works pretty well in real life.

      Kyusho would be incredibly useful if MMA bouts began like real self-defense situations and real-life fights. That is to say with both parties standing in a natural posture (with their hands at their sides) about 2 to 3 feet away from each other.

      But even under the current (less than fully realistic) set of rules, these methods are used with fair frequency and with fair success.

      Of course, it is worth mentioning that MMA bans the use of many of the most useful kyusho points. For instance attacks to the eyes, testicles, points in the throat area, points on the back of the head/neck (so-called "rabbit punches"), points on or very near the spine, and even some blows to the vital points in the kidney area are strictly banned in MMA competition.

      I'm not saying such blows should not be banned in sporting events, as it goes without saying that they are fairly dangerous targets (which is why they are called kyusho).

      However, with the exception of the attacks to the eyes, many Okinawan stylists can easily shrug off those blows like they never happened. See my video "Another Okinawan kiko demonstration"

  2. I just discovered your blog. It is incredible. Thank you.