States of 'Muhyeong' and 'Yuhyeong' in ITF Taekwon-Do

At the end of 2023 I gave a presentation at Youngsan University's 4th International Taekwondo Conference on the muhyeong-principle in ITF Taekwon-Do. It has been my intention to develop it into an academic paper to submit with a journal, but I've been too distracted to work on that, so I'm deciding to share my draft here on my blog to the benefit of the ITF community, while I hopefully finish the paper for publication in the future. 

From Decisiveness to Adaptability: The Muhyeong-Principle in (ITF) Taekwon-Do

Introduction: Karate's Kime and Taekwon-Do's Jipjung

Taekwondo developed from a Japanese karate—mostly Shotokan Karate—foundation and although Taekwondo evolved into a uniquely Korean martial art, it still retains remnants of both technical methodology and philosophy that are rooted in Japanese martial culture. One example is the notion of kime (決め), which refers to the conspicuous full body tension performed by the karateka at the final moment of a technique. From a technical perspective, this full body tension is supposed to make the body into a solid, immovable structure to fully transfer the technique’s force into the target and prevent possible negative effects from any rebound force. The term kime literally translates as “decision,”^[1] and connotes firm decisiveness; in other words, kime suggests an unwavering execution of the technique decided upon. The isometric concentration of the whole-body musculature in kime is a manifestation of the karateka’s decisive technique. This unwavering decisiveness also manifests in the early formation of the attacking or blocking tool. When performing techniques in karate, the practitioner will keep the hand shape the same from start to finish. For instance, if the technique to be performed is a punch the hand will remain in a fist shape from beginning to end; similarly, if the technique is to be an open-handed strike, the hand will be kept in the knife-hand shape throughout the execution of the movement. This consistency in the “form” of the hand reflects kime’s connotation of an unwavering decision: once the decision to perform either a punch or a strike is made, it is resolutely executed. Within the broader context of Japanese martial arts, one may understand kime, then, as a technical expression of another idea in some Japanese martial arts, including Shotokan karate, namely: ichigeki hissatsu (一撃必殺) which translates as “one punch, certain death” or the more euphemistic expression ichigeki hitsutou (一撃必倒), “one punch, certain victory”.^[2] As such, kime which is primarily a biomechanical feature in karate also lends itself to psychological or philosophical interpretation.

Taekwondo inherited a version of kime from karate. But in taekwondo it is known as jipjung (집중), which translates as “concentration” or “focus”; the term is based on the hanja 集中, which literally translates as gathering everything together to a central point. As such, Taekwon-Do’s jipjung is employed “to concentrate every muscle of the body … towards the appropriate tool … at the proper time … onto the opponent’s vital spot”^[3]. 

In Kukki Taekwondo (the style of Taekwondo under the auspices of the Kukkiwon) the shape of the attacking or blocking tool is also predetermined like in karate; in other words, a punch will start from the hip in the shape of a fist, and a knife-hand strike will also be in the knife-hand shape from the very start of the technique. While the physical manifestation of kime is still visible in the performance of taekwondo’s fundamental movements—for instance in poomsae—, the associated Japanese philosophy of a decisive, victorious action is somewhat lost in translation, as the Korean word jipjung doesn’t have the same decisive connotation as is the case with the Japanese word kime. Instead, taekwondo’s jipjung implies the bringing together of all elements, movements, circumstances, and mental focus into a focussed point; in other words, one’s total energy focussed into the metaphoric bullseye by means of a perfect technique. 

ITF Taekwon-Do also retained the kime / jipjung principle of a whole-body isometric contraction at the final moment of the technique; however, the predetermined formation of the attacking or blocking tool has disappeared from ITF Taekwon-Do’s techniques. In ITF Taekwon-Do, techniques must initiate from a state of relaxation, and unnecessary tension of muscles while performing a movement is strongly discouraged as any engagement of antagonist muscles is believed to negatively affect the speed and resultant power with which the technique can be performed. Therefore, in performing a hand technique, the hand is kept relaxed and without any predetermined form; it is only concentrated into its appropriate shape moments before impact. For example, when performing a punch, the hand remains in “no-form” (neither flexed open nor tightly clenched closed) ^[4] and only concentrates into a fist as the hand nears the target; similarly, when performing a knife-hand strike the hand is relaxed into the hand’s natural unengaged shape and not prematurely opened into the knife-hand shape—the hand will only stiffen into this striking tool prior to contact with the target and during the moment of jipjung. 

States of Muhyeong and Yuhyeong

While the full body tension and the moment of contact with the target does have a designation in Taekwon-Do, namely jipjung, thus far this relaxed methodology that encourages a “no-form” shape of the hand does not have an official nomenclature—apart from general descriptions such as “relaxed” or “lightly clenched” and “not tightly clenched”. After research and discussions with various Korean martial art scholars I decided to designate the Sino-Korean word muhyeong (무형, 無形), which literally translates as “no form” or “without form”—implying something that is “intangible” or “amorphous”—for this principle. This is a fitting description for this relaxed “no-form” aspect in ITF Taekwon-Do techniques before they have morphed into a recognizable tool such as a knife-hand or fist shape. Inversely, the word yuhyeong (유형, 有形), meaning “physical form” or “tangible shape” can be applied to describe the attacking or blocking tool when it has “formed” into its appropriate shape moments before and during the final jipjung-climax. 

Of course, it goes without saying that when we describe the hand as being in a state of muhyeong we do not mean it literally, as if the hand is liquid or vaporous. The hand still retains the natural bio-tensegrity or fascintegrity that is innate to the living structure of complex organisms.^[5] Also, the wrist is never allowed to go limp, but is kept in a neutral position, neither bent up or down nor left or right. A hand in a state of muhyeong simply means that it is naturally relaxed and not formed into a blocking, attacking, or grappling tool. Contrariwise, a hand in a state of yuhyeong is formed into a specific tool. Muhyeong has the primary biomechanical function of keeping the limb relaxed (iwan, 이완, 弛緩), free from unnecessary antagonist muscle tensions so as not to hamper the technique’s speed. 

Techno-Philosophical Interpretation

Apart from its primary function as a method for relaxing antagonist muscles, the muhyeong-notion is also ripe for further interpretation. 

Different Approaches: Decisiveness versus Adaptability

In Karate, kime, as a “decisive” action, implies that once the karateka decides on a technique they ought to be fully committed in its execution, hence the shape of the attacking or blocking tool is predetermined and remains the same from start to finish. It would be considered “wrong,” within the Karate-context, to change one’s mind halfway through the execution of the technique. For instance, once the karateka decides to do a fore fist punch, it is improper to second-guess the decision and suddenly change the technique into a fingertip thrust, as techniques should be performed without hesitation. As such, kime in Karate resonates with a similar idea in several Japanese martial arts, namely sutemi (捨身). A literal translation of sutemi is “abandoning the body,” suggesting self-sacrifice. The implication is a total commitment to every technique without thought of any repercussions. Hence, the highest point one can achieve in Judo is called an “ippon” (一本), translating to one full point or decisive victory^[6]. Both kime and ippon emphasize the importance of decisiveness and achieving a clear outcome attained by complete commitment to executing a technique with full intention and power.

On the other hand, the muhyeong-principle in ITF Taekwon-Do frees the practitioner from such predetermination. Since the attacking or blocking tool only fully manifests in a proper shape (yuhyeong) towards the end of the movement, the Taekwon-Do practitioner is theoretically free to adapt the technique as the situation changes. Therefore, it is quite acceptable within the Taekwon-Do context to change a technique strategically: a punch may become a backfist strike; a front kick may suddenly change into a turning kick; a side kick might suddenly morph into an offensive hook kick. Those familiar with Taekwon-Do sparring will immediately recognize this as a common strategic feature of Taekwon-Do. For instance, kicks are often adapted mid-execution to adjust for the opponent’s movements or to exploit new openings in their guard. Furthermore, this helps to prevent a level of telegraphing, because even when the movement has started the exact technique is not fully knowable until near the end of its execution. 

Relation to East Asian Philosophy

I believe that this muhyeong concept is consistent with some East Asian philosophical ideas that have a long historic association with East Asian martial arts theory. 

Eum-Yang

First, the Daoist concept of taegeuk, (태극; Chinese: 太極, taiji) and its associated eumyang-principle (음양; Chinese: 陰陽, yinyang), is a core idea in East Asian cosmology and often used by East Asian martial arts as a theoretical bases for describing techniques. There are already several approaches for understanding the eumyang-principle in taekwondo. For instance, Dr Stephen Capener argues for interpreting the eumyang-principle as “full and empty space” to explain Taekwon-Do sparring strategy.^[7] For him, during a sparring match, the dynamic interchange of the competitors’ limbs in motion and inevitable appearance and disappearance of viable targets for attack represent “full” and “empty” spaces. An understanding of such full and empty spaces allows for both strategic sparring application and philosophical interpretation. Furthermore, some Korean scholars promote the idea of gangyu (강유, 剛柔), meaning “hardness and softness,” as an application of the eumyang-principle in Taekwon-Do but viewed through a Neo-Confucian lens. Gangyu can basically be understood as those particular binary aspects in Taekwon-Do, such as offensive and defensive techniques. My proposal of “form” and “no-form” (in ITF Taekwon-Do) is likewise an exploration of the eumyang-principle. If a Taekwon-Do technique has a moment of deliberate high tension, where the whole body is concentrated into an unmoving, isometric firmness (in other words, jipjung), it only makes sense that it should also have the opposite, namely a phase of deliberate relaxation (iwan) and fluidity. Similarly, since a technique is only recognized as such at the final moment when it expresses into its clearest form (yuhyeong), it goes without saying that it also has a preformed or amorphous state (muhyeong). 

Muwi 

This muhyeong idea, which allows a practitioner a level of liberty to adapt the technique naturally according to changing circumstances resonates with yet another concept from Daoist philosophy, namely muwi (무위; Chinese: wuwei, 無為), which translates as “non-doing” or “no effort”. Within Daoist teaching, this doesn’t literally mean to not do anything, but rather not to force a situation and instead allow things to unfold naturally. Many martial arts have taken up the muwi principle to mean that a good technique is one in which the greatest result is achieved with the least amount of effort. This principle of efficacy directly relates to the biomechanical purpose of muhyeong which is to ensure that only the necessary agonist muscles are engaged in their proper sequence, and the antagonist muscles are appropriately relaxed, subsequently resulting in the most efficacious movement. 

Mugeuk and Mushim

Furthermore, in Daoist thought mu (無) does not mean mere nothingness; instead, it relates to the “Void” (無極; Korean: mugeuk, 무극), the place of incipience, which contains all potentialities. For the trained martial artist this connects to that spontaneous, reflexive, and masterful bringing forth of the right technique at the right time; in other words, the most appropriate technique hitting the best target at just the right moment. This is different from the kime-concept that implies an active decision. From a Daoist paradigm, the most appropriate technique is not “decided” but rather allowed to manifest without conscious thought naturally and spontaneously. Just as the hand can be described as in a state of muhyeong, so the whole person—body and mind—may manifest muhyeong. This is not conceived as a structureless body and unconsciousness mind, but rather as a body filled with potentiality and a mind open to all options. Daoist and Buddhist meditative practices calls this mental state mushim (무심; Chinese: wushin, 無心; Japanese: mushin). Mushim suggests a mental state of no-mindedness; or a “mind empty of all thought or emotion” so that it is able “to respond to any external stimuli, allowing free expression of any response technique.”^[8] In other words, the ability to do defensive and counter-attack techniques reflexively, without thinking. 

This muhyeong state is of course a transitional state, from a state of potentiality to the yuhyeong state of actuality. As the transition happens, the various potentialities or technique possibilities become fewer and fewer, until finally only one possibility remains. In practise this means that the movement starts out relaxed, but slowly more muscles will become engaged until finally all muscles are engaged. Thus, yuhyeong and jipjung converge. When, from the vast sea of potential techniques, the most appropriate technique is actualized, perfection occurs. Or as Capener puts it: “bringing order to chaos through skillful technique.”^[9] Of course, for this to occur the practitioner must have physically mastered various potentialities, which is a great arsenal of efficacious techniques (or fundamental movements). Only then can the most appropriate technique come forth without conscious thought or physical restraint. As such, muwi as a philosophical extension of muhyeong does not mean no effort in training, but rather so much training and mastery of techniques that when a technique is performed it seems effortless, which is—as all martial artists know—the difference between the novice and the expert. This implies that fundamental movements ought to be trained—or rather—drilled to such a level that they can manifest effortlessly. 

Practical Considerations

Returning from the philosophical to the practical, there are important technical aspects regarding the point of impact with the target that is crucial to discuss. We may ask: ‘When, during the execution of the movement, is the moment of contact with target?’ To make the question more tangible, let’s focus on a specific technique, the front fore fist punch: ‘When performing a front fore fist punch, at what point of the arm’s extension (and the hand’s rotation) should the fist reach its target?’ Asked differently, ‘When should the full transformation from muhyeong to yuhyeong occur?’

There are two reasons these questions are crucial. First, if the hand is still in a state of muhyeong at the moment of impact with the target, there is a high possibility of the hand getting injured since it is not formed into a proper, stable attacking tool (yuhyeong) that can withstand the force of the impact. It is therefore imperative that the hand not make impact with the target too early. Second, all techniques accelerate and then suddenly decelerates at the end of the movement. The deceleration can happen either because it reached its target (e.g., the fist hits the opponent), or because the arm has reached its full extension, which means it naturally stops. The implication of this is that since force is the product of mass times acceleration, the highest moment of the technique’s force cannot be at the very end when the limb is fully extended, as by that time it has decelerated to zero. Ergo, the highest moment of potential force is a point along the trajectory, when the limb is at its highest point of acceleration, before any deceleration starts. Therefore, we want to ideally hit the target at this point when the limb’s speed is at its greatest, which is a point before the limb is fully extended. But how can we know when that is?

Taekwon-Do convention advocates that when performing a front fore fist punch, the punch should rotate upon contact with the target. Various reasons for this rotation are proposed, but I’ll leave that aside for now. What I want to focus on here is simply that, according to tradition, the fist should rotate on the target. What this implies, then, is that the moment the fist starts rotating is also conceivably the moment of initial impact—the full rotational corkscrew of the fist is supposed to coincided with the deeper penetration of the technique towards the true target that is beyond the surface skin. For instance, when we aim for the solar plexus, we are not merely aiming for the spot right under the sternum, but rather for a point deeper within the torso.^[10]

Different instructors promote different times in the execution of the punch for the rotation to occur. Some suggest the final third of the movement, others say at the last quarter before full extension. Unfortunately, scientific studies that measure the highest moment of acceleration in all ITF Taekwon-Do techniques are yet to be done.^[11] There are, however, some studies with regards to punches in Karate and Kukki Taekwon-Do worth mentioning. Based on punching experiments mentioned by Master Nakayama, the “maximum speed occurs at just around 70 percent of full extension”^[12]. An academic article focussing on Karate punches states that the “maximum speed was recorded as a point between 70 and 80 [percent]” of full extension.^[13] The Kukkiwon’s Taekwondo Textbook (2022) suggests that this point is at “80% of the arm’s length”.^[14] So the oral tradition in ITF Taekwon-Do that advocates for the rotation to start at around the final quarter of the movement seems to be correct.

What this suggests is that by this point (i.e., the point of highest velocity), yuhyeong (i.e., the formation of the attacking tool) ought to occur. Of course, the point of highest velocity will be slightly different depending on the technique and also purpose. But until scientific research is done to determine the likely points for different techniques, we can—for practical purposes—assume the same rule of thumb that the point of highest velocity occurs at roughly 75% of the full extension of the limb, or around the final quarter of the technique.

Earlier in this discussion it may have seemed that I equated yuhyeong and jipjung. However, based on the preceding it is obvious that this is not the case. Yuhyeong occurs slightly prior to jipjung. Yuhyeong (the formation of the tool) happens at around three-quarters of the movement, while jipjung (isometric concentration of the whole body) is a bit closer to the end of the movement. However, the precise commencement of the two are within fractions of a second of each other. Though they do conclude at the same time. 

Conclusion

A very important departure in ITF Taekwon-Do’s evolution out of Karate is the muhyeong-principle. This kinaesthetic principle has technical, strategic, and philosophical applications and implications. Technically it contributes to more relaxed movement which are theoretically capable of greater acceleration. It is important, however, to keep practical considerations in mind when employing the muhyeong-principle. While muhyeong may have some technical advantages, it may also lead to possible injuries when practitioners fail to apply yuyeong in time. For instance, if it is not formed into an appropriate blocking, attacking, or grappling tool before contact with the opponent, the hand might be injured. Strategically, the muhyeong-principle allows for greater adaptability. Taekwon-Do techniques are allowed to change mid-execution to adapt for changes in the combat dynamics. This level of freedom may have contributed to Taekwon-Do’s creative expression that led to the creation of various innovative techniques. And philosophically the muhyeong-principle resonates with Daoist concepts such as muwi and mushim. For people who find this East Asian philosophical interpretations too esoteric, I recommend another interpretive lens, that of Sport Psychology. The same muwi and mushim ideas can be understood as part of the “flow” state, which is a mental condition where an athlete is fully immersed in their performance; it is often described as being “in the zone,” where athletes experience a merging of action and awareness, making their performance effortless and automatic.

^[1] The equivalent Korean word is gyeoljeong (결정, 決定), meaning decision or resolution. However, this term is not commonly employed to describe Taekwon-Do techniques.

^[2] General Choi famously also made a calligraphy of this phrase (一撃必倒), which is printed in the ITF Taekwon-Do Encyclopaedia. The Korean (일격필승) Romanizes as ilgyeok pilseung.

^[3] Choi, H. H., (1999). Encyclopaedia of Taekwon-Do. Vol. 2, p. 20. 

^[4] Another Korean martial art, Subyeok-Chigi (수벽치기), which has a similar concept of not forming the attacking tool prematurely, calls this hand shape banjum (반줌), literally “half fist”. I use this term when I want to discuss the relaxed hand shape before it concentrates into a tool specifically; when I want to keep the philosophical idea of muhyeong and yuhyeong out of the discussion.

^[5] Bordoni, B., Varacallo, M. A., Morabito, B., and Simonelli, M. (June 03, 2019). “Biotensegrity or Fascintegrity?” Cureus 11(6): e4819. DOI 10.7759/cureus.4819

^[6] The ippon is to Judo what the knockout punch is to Western boxing: clear victory.

^[7] Capener, S. D. (1995.) “Problems in the Identity and Philsophy of T’aegwondo and Their Historical Causes.” Korea Journal. (1995: Winter.)

^[8] Rielly, R. L. (1998). Complete Shotokan Karate: The Samurai Legacy and Modern Practise. (p. 80.)

^[9] Capener, S. D. (1995.) “Problems in the Identity and Philsophy of T’aegwondo and Their Historical Causes.” Korea Journal. (1995: Winter.)

^[10] The solar plexus is a common target in many martial arts. However, few people realize how deep the solar plexus is within the body. What is known as the “solar plexus” is a cluster of nerves roughly 10-12 cm from the front surface of the body, nearer to the front of the spine. It is very unlikely that one would penetrate the body from the front with a punch deep enough to reach the solar plexus. The usual effects we witness from strikes to the solar plexus is probably due to the shock to other organs that are much closer to the surface, such as the diaphragm. 

^[11] Regrettably, I doubt there is an ITF organization with the desire to start such a project even though such studies would be invaluable to the scientific understanding of ITF Taekwon-Do. I can only hope that my work inspire other individual Taekwon-Do scholars with the knowledge and means to undertake such research.

^[12] Nakayama, M. (1967). Dynamic Karate. 

^[13] Walker, J. D. (1975). “Karate Strikes”. American Journal of Physics. Vol 43:10 (pp. 845-849).
^[14] Choi, C. & Lee, S. (2022). Taekwondo Textbook: 2 Basic. Kukkiwon.

Quick Notes on Basics and Fundamental Movements

A while ago I was scanning through this blog searching for a post on "Basics", which I was certain I wrote years ago. In my memory the title of the post was something along the lines of "Prototypical Movements". However, to my frustration, I couldn't find the post I was looking for. The closest I got to it was a paragraph written in another post on the value of the patterns. Then I thought, maybe I had written the essay, but possibly forgot to post it, so I searched for it in my old Taekwon-Do folders, but that search came up empty as well, except for a short passage in a draft document in which I discuss Taekwon-Do's pedagogy. It is a pity that I can't find the text I thought I had written; it might be that it was completely conceptual and I just never got round to writing it. The gist of the idea is that there exists a category of movements that are more foundational than the Fundamental Movements, and time spend on trying to distill and understand these "basics" are of immense value. I decided to post the excerpt from the aforementioned draft below:

Notes on Basics and Fundamental Movements

 

Fundamental movements are the vocabulary of Taekwon-Do. Each fundamental movement is a specific identifiable technique using a specific stance and specific (attacking or blocking) tool aimed at a specific target on the opponent and which can usually be found described or alluded to in the ITF Encyclopedia. These individual techniques should first be taught by a qualified instructor. Thereafter, the practitioner can easily practise these movements by themselves. There is no question as to their importance and even grand masters will often go back and practice specific fundamental movements. 

There are supposedly over three thousand individual fundamental movements in Taekwon-Do. A common error people make is to try to accumulate techniques…trying to learn each of these hundreds of movements. This is not a good approach. A much better approach is to practice the basics and grasp the underlying principles. 

I differentiate here between fundamental movements and basics (basic motions), which are the gross motor movements that fundamental movements share. If fundamental movements are the vocabulary, the words, of Taekwon-Do, then basic motions are the phonics, i.e., the sounds used to make those words. Put differently, basics are the building blocks of fundamental movements, and many fundamental movements use nearly the same basic motions. There are far fewer basic motions, and one is exposed to all the important basics very early on, probably within the first few colour belt patterns. To excel in Taekwon-Do, it is better to identify and perfect the basics (gross motor movements), rather than try to amass all the individual fundamental movements.

I will give a few examples. First, each stance should be considered a basic and transitioning between stances are basics as well. Next, the shared gross motor movements used in techniques are what constitute most of the basics. For instance, the pulling-hand that is brought to the hip with nearly every punch or thrust is such a basic. The difference between a walking stance high or middle front fore fist punch, a long fist punch, an open fist punch, a flat-fingertip thrust, a twin-fingertip thrust, and an arc-hand thrust is almost entirely based on changing the unformed hand into a different attacking tool moments before impact: the overall gross motor movement is almost exactly the same for all these punches and thrusts. Similarly, the outer-forearm outward blocks (irrespective if they are high, middle, or low), the knife-hand blocks, and even knife-hand side strikes share another basic motion—the arm is brought across the body with the palm facing somewhat up, and then moved towards the outer edge of the body while the arm rotates so that the palm faces the other way. Rather than learning these fundamental movements as individual techniques, it is better to ingrain the gross motor movement of the arm and body and only learning to adjust the end positions appropriately. You will also notice that many fundamental movements are simply a basic movement (gross motor movement) stopped somewhere else along a trajectory. For instance, a middle vertical punch is simply a regular middle punch that stopped short of its target; a knife-hand block is a knife-hand strike before full extension; a knee kick, such as a front or turning knee kick, is a regular kick without the final snap of the lower leg. 

In short, there are few gross motor movements to master, and each fundamental movement requires only slight tweaks to differentiate between them. I don’t mean to suggest that you do not need to practice fundamental movements; however, focusing on mastering the basics—the gross motor movements—will bare much more and faster results as the principles in one basic motion are directly applicable to all the different fundamental movements that share that basic motion.  

Fundamental movements are often trained on the spot or as line drills while stepping, sliding, dodging, or jumping forwards or backwards. This is appropriate, although I would also add side-steps, and diagonal movements as part of such drills. Furthermore, once a fundamental movement is understood and done with relative mastery, it is much more useful to practice combinations of fundamental movements, rather than one fundamental movement at a time. It is good to practise combinations of fundamental movements that seem to fit logically together and have a sensible flow. The Korean term for such sequences is pum 품, which are the sequences of movements that make up the patterns. It is very important to practice the pum from a pattern before practicing the pattern in its entirety. 

(Occasionally instructors may also combine sequences that are unnecessarily difficult, i.e., that do not have a natural flow to them. This challenges both body and mind and few things encourage learning than struggling to figure out a complex problem.)

While line drills and pum-practice for lower ranks are trained according to movement principles associated with “traditional” movement, higher ranking practitioners can transcend such formalized training and move in a “freer” manner, with stances and rhythms that are less fixed—by practicing the combinations as if they are doing free sparring. In other words, the drills are more akin to “shadowboxing”. This does not mean that the formal stances and rhythms are thrown out the window. Instead, traditional stances and rhythms are moved in and out of dynamically, rather performed in a fixated “traditional” manner.
 

"Sine Wave" in Korean

Sine Wave Motion in Korean

By Sanko Lewis, PhD

From relatively early in Taekwon-Do’s evolution, there has been a type of “verticality”—i.e. up-and-down movements. The term “verticality” was coined by Judy Van Zile, an ethnographer studying Korean traditional dance. She uses the term to describe the conspicuous characteristic of bending-and-straightening of the knees (and other parts of the body) in Korean traditional dance. Such bending-and-straightening of the knees also became a feature of Taekwon-Do, which differs from Japanese Karate in which Taekwon-Do has its roots. Karate prefers little or no “verticality” during stepping. Prototypical Taekwon-Do (i.e., the “Taekwon-Do” of the late 1940s and 1950s) did not have “verticality” as it was basically still Karate, and participants moved according to Japanese body culture. However, “verticality,” which is innate to traditional Korean body culture, slowly seeped into Taekwon-Do movements. By the 1960s, “verticality” was already implied in the “knee-spring” notion. (This focus on the bending or 'spring'-action of the knee is an iconic feature of traditional Korean body culture.)

Initially ITF Taekwon-Do stepping was done in an up-down motion. Around 1981-1983, under the guidance of General Choi Hong-Hi, this up-down execution was amended to a down-up-down execution (or relax-rise-fall, as I prefer to describe it), which became known as the “sine wave motion.” In some of his writings, Stuart Anslow identifies a seminar in 1983 as the year the term “sine wave” became used to describe this down-up-down kinetic expression. This concurs with the first edition of the Korean version of the ITF Encyclopedia in which the English term for this motion is provided as “싸인 웨이브,” which is the transliteration of the English term “sine wave.”

The common assumption is that General Choi appropriated the term “sine wave” to infuse a scientific notion to this type of movement. This is an assumption I held too for quite some time, but it has always made me rather uncomfortable because it is not scientifically sound. The contemporary down-up-down manifestation mimics the shape of a cosine wave, not a sine wave that has an up-down-up shape, if we start at 0 (i.e., X = 0).  

I began to wonder what term General Choi used in Korean, so I looked up what term is used in my Korean versions of the ITF Encyclopedia. There are two synonyms in Korean for “sine wave”: jeonghyeon-pa 정현파 and sain-pa 사인파 (the latter is simply an Anglicanism of sine-wave). Unexpectedly, neither of these words are used in the Korean versions of the ITF Encyclopedia. The Korean term has actually no relation to this scientific concept. Instead, the Korean version of the ITF Encyclopedia uses the term hwaldeung-pado 활등파도, which literally translates as “bow-back waveform.”

What does this mean? Literally, bow-back refers to one side of a bow (archery weapon). The English collocation is “back-of-the-bow,” and refers to the outside of the bow, which is the side facing away from the bowstring. Whereas the side that faces the bowstring is called the belly-of-the-bow. When the bow is stringed, and the archer draws the bow, the wooden bow is arched into an obvious curve (the typical bow shape).

In other words, the original Korean term simply refers to the curvature of the wave form, which should resemble a smooth crescent or bow-like shape; this shape is contrasted in the Encyclopaedia with the “saw-tooth wave” (abrupt up-and-down movements rather than naturally curved movements) and the “horizontal wave” (keeping one's head level throughout the movement), which are incorrect ways of moving in ITF Taekwon-Do.

Upon further investigation I was surprised to note that the transliteration of the Korean term in the 1999 version of the English Encyclopedia (and presumably all subsequent editions) is not hwaldeung-pado 활등파도. Instead, it is yulson. Because the English version of the Encyclopedia doesn’t use hangeul (the Korean alphabet), but only transliterations of the Korean words, it required some effort to try and figure out what the word means. “Yulson” can be written in Korean in various ways 율손, 율선, 열손, 열선—each with different possible meanings. Discussions with native Korean speakers seem to all agree on the second variant: 율선, which is Romanized according to South Korea’s current system as “yulseon.” Finding a proper translation for yulson 율선 is not straightforward.

The translation for yulson 율선 律旋 given by the dictionaries I checked is “melody”. This translation was affirmed to me by a Korean Taekwon-Do master (8th Dan) I consulted. This word is hardly used in modern Korean. A more recognizable term for “melody” is garak 가락, which dictionaries provide as a synonym for yulson 율선. If this is indeed the correct translation, my Korean friends suggest that yulson implies the melodious movement of a tune. It is noteworthy that Korean traditional music has a “curved melodic line with typical vibrato known as nonghyeon or nongeum”—I got this explanation from Professor Sheen Dae-Cheol 신대철 of the Academy of Korean Studies, during a lecture on the aesthetic characteristics of Korean traditional music. If this is the correct understanding of yulson 율선, then we may assume that it refers to the “curved melodic line with typical vibrato,” which may be represented by the oscillating shape of a sine wave.

However, with all due respect to my Korean friends, I’m not completely convinced about the “melody”-hypothesis. The reason for my doubt is that suffix “-son” [-선]. The same page in the ITF Encyclopedia that mentions yulson 율선 as translation for sine wave, also lists soopyong-son and topnal-son as translations for “Horizontal Wave” and “Saw Tooth Wave” respectively. (Notice the same “-son” suffix used in these words.) In the Korean versions of the ITF Encyclopedia, the Korean term is not “-son”, but “-pado” 파도. The relevant pages in the Korean version of the encyclopedia (Volume 4, p. 195) and the Korean version of the condensed encyclopedia (p. 322) lists Sine Wave as 활등파도 hwaldeung-pado, Horizontal Wave as 수평파도 soopyong-pado, and Saw Tooth Wave as 톱날파도 topnal-pado. It is clear, therefore, that “-son” -선 has to have the same or similar meaning as “pado” 파도 which literally translates as wave.

Therefore, a more likely translation of -son is based on a different hanja 線 that means “line.” This better matches the accompanying pictures in the Encyclopedia that shows drawings of a sine wave line, a horizontal line, and a saw tooth line.

This brings us back to the meaning of yul 율 in the term yulson 율선. I suggest that it is based on another hanja 率 that means “rate” or “frequency.” For instance, one’s pulse is biyul 비율, literally “blood-rate”. The alternative hanja 律 means “a law, a rule, a statue, a regulation” which doesn’t seem to fit. On the other hand, “rate/frequency” 率 seems sensible, because a sine wave can accurately be described as a line depicting a frequency. This matches with how some (North) Korean masters describe the sinewave motion as “rhythmic motion”.

Consequently, based on the Korean terms hwadeung-pado (back-of-the-bow wave) and yulson (melodic shape or frequency line), the intention was not to invoke scientific notions of “sine” or “cosine” waves in particular. The picture in the Encyclopedia doesn’t provide us with a single truncated sine wave (or cosine wave), but instead shows a continuous wave. The argument whether the movement looks more like a sinewave or a co-sinewave misses the point. General Choi was using a metaphoric descriptor to depict the smooth curvature of the stepping motion. The stepping should be smooth like a (sine)wave or smooth like the back-of-the-bow. The metaphors are clearly intended to suggest smooth “verticality”; which General Choi juxtaposed with a stepping motion that has no vertical movement (“horizontal wave”) on the one hand or a rugged (“saw-tooth”) movement on the other hand.

While the Korean Encyclopaedia uses the term “bow-back waveform” 활등파도, it also includes the English translation as “싸인 웨이브,” which is the transliteration of the English term “sine wave.” It is not clear why General Choi chose the metaphor of a bow in Korean, but the sine wave in English. It might have been that he thought few Western people are familiar enough with the archery weapon; or, maybe he did choose to use the scientific term “sine wave” to add some scientific notion to the technique.

Nevertheless, another question may be asked: why the change from the original up-down to the current down-up-down motion for most standard movements in ITF Taekwon-Do? The common assumption that the term “sine wave” (or “co-sinewave”) explains the three phases (down-up-down) is not supported by the Korean terminology used by General Choi. The Korean terms hwadeung-pado and yulson, whether understood literally or metaphorically, do not suggest any number of phases (ups-and-downs) in the motion.

There are some possibilities: 

Several people believe it was a political move by General Choi to discredit masters that were not loyal to him and had left the ITF. By introducing this change the General could claim that they are not teaching the founder’s “authentic” Taekwon-Do. A proponent of this view includes Mr. Alex Gillis, the author of the historical exposé A Killing Art: The Untold History of Tae Kwon Do.

Another possibility proposed by myself (a Korean body culture researcher) and Dr He-Young Kimm (Korean martial arts historian and author of Taekwondo History) is that the General introduced a three-beat rhythm as part of his continuous effort to make Taekwon-Do a truly Korean art. Moving according to a three-beat rhythm can be seen in Taekkyeon (a Korean folk martial art) as well as traditional Korean dance, and is the basic rhythm used in Korean traditional music. The change to a three-beat rhythm is a departure from the Japanese two-beat rhythm found in Karate. The three-beat rhythm in ITF Taekwon-Do is achieved by an initial conscious relaxation, followed by an up-down (or rise-fall) movement when executing many techniques. This initial relaxation was, as far as I am concerned, an ingenious contribution to ITF Taekwon-Do’s makeup. It has completely changed the way Taekwon-Do is performed—moving it away from Taekwon-Do’s Karate roots towards a more naturalistic Korean way of moving (emphasizing relaxation over tension). Of course, my and Dr. Kimm’s cultural hypothesis doesn’t exclude Mr. Gillis’ political hypothesis.

In short, the term used in the Korean versions of the ITF Taekwon-Do Encyclopaedia to describe the stepping motion is not “sine wave”—but rather “back-of-the-bow waveform”; in other words, a wavelike movement like the smooth curved shape of a bow. It should obviously be understood as a visual metaphor, and not as some inclusion of a trigonometrical function to increase power. 

The Long Fist Punch (aka Leopard Fist)

The Long Fist Punch (긴주먹)

The long fist (gin-jumeok 긴주먹) is one of ITF Taekwon-Do’s less known “fist” postures. It is not a particularly common striking method although I think it could prove devastating if used appropriately.

The long fist is formed by curling the front and middle knuckles of the fingers and pulling the thumb back, similar to the knife-hand posture. The result is a flattened hand position, with the middle knuckles protruded as the attacking surface. The name “long fist” is due to the slightly longer reach than the regular front forefist punch.

The main targets to attack with the long fist are the Adam’s apple and temple. Secondary targets may include other soft target areas such as the nerves on the side of the neck and Jugular veins, the trachea, the spaces between the ribs, the armpit, philtrum, bridge of the nose and even the eyes. The hand position need not be horizontal; it can be turned vertically, for instance, or diagonally, depending on the target. The long first also works well in a raking motion: raking the knuckles up and down the sternum creates quite a nasty sensation that causes people to retreat, or quickly raking the knuckles over the back of someone’s hand that is holding onto you often causes them to release their grip.

The long fist should not be used to punch hard targets like the skull as one is likely to injure one’s own hand.

The long fist works well for narrow targets such as the philtrum.

For people with long nails that can’t roll the hand into a full fist, the long fist may be a compromised alternative, although it doesn’t have the same range of targets as a front forefist punch does. Nevertheless, the same long fist hand posture may also work like a knife-hand strike with hardly any disadvantages. Also, with only minor adjustments the long fist hand posture can become a bear hand, under-fist, and back-hand strike. Alternatively, with the wrist pulled back it becomes an open fist. It is therefore a very useful default hand posture because it can so comfortably morph into other hand-weapons.

The long fist was most likely inherited from Karate where it is known as hiraken tsuki. It is very likely that Karate got the technique from Chinese martial arts, where it is often known as the leopard fist, which is a primary hand technique of Leopard Kung Fu, one of the Five Animal Styles. One can also find it in Choi Li Fut, and in more modern combat systems like Krav Maga where it is referred to as a half fist punch. 

The Fingertip Hand Technique

Walking stance straight fingertip thrust (걷는서 선손끝 뚤기)

The photo above shows a straight fingertip thrust in walking stance 걷는서 선손끝 뚤기 (geodneunseo seon-son-ggeut ddulgi). The finger tip 손끝 (son-ggeut) hand position in ITF Taekwon-Do requires the tips of the forefinger, middle finger, and ring finger to be aligned. Notice how my three fingers are aligned in the photo. Because the length of fingers differ greatly from person to person, the degree to which one has to bend particular fingers to align with the shortest of the three fingers will be very specific to each individual. Of course, for most people the middle finger is the longest, hence it will be bent the most. The tips of the three fingers should be aligned at the front, but also pressed tightly against each other; in other words, the index finger and ring finger should put pressure against the middle finger. It is important to ensure that all three fingertips point forward. The middle finger which will be bent the most might have a tendency to point down, which is wrong, as shown in the photo below.

This photo shows an incorrect alignment of the fingertips.
In this photo, the tip of the middle finger is point downwards
instead of forwards like the index finger and ring finger.
For a proper technique, all the fingertips should point forward.

You can practice the correct positioning by tapping the three fingers together on a hard surface. This technique is designed to work with short clipped nails. (There are techniques such as the "cross-cut" aimed at the eyes that may benefit from longer nails, but the fingertip thrust works best with short nails.)

For a fingertip thrust, the hand can be turned vertical or with the palm either facing up or down, depending on the target aimed for. The vertical hand orientation is known as the spear hand or straight fingertip 선손끝 (seon-son-ggeut) as seen in the photo, the palm facing down orientation is known as the flat fingertip 어픈손끝 (eopeun-son-ggeut), and the palm facing up orientation is known as the upset fingertip 뒤집은손끝 (dwijib-eun-son-ggeut). There is also a variation where the fingers are at a right angle to the palm, which is known as the angled fingertip 호미손끝 (homi-son-ggeut).

Although a conditioned technique can be tough enough to pierce wooden boards, the technique is ideal for attacking nerve plexuses, such as the solar plexus (diaphragm), the philtrum, the bronchial plexus under the arm or the side of the neck, the nerves between the ribs, the pelvic region, and so on. Other soft targets such as the eyes and throat (windpipe) can also suffer damage from a finger tip thrust.

Fingertip attacks are classified as thrusting techniques in ITF Taekwon-Do. Thrusting techniques #뚤기 usually refer to techniques aimed at nerves and soft targets. Thrusts usually hit these vital spots straight on. Punches #찌르기 also usually attack linearly, but are generally aimed at harder targets; for instance, the sternum and ribs, or jaw (chin and angle of mandible) and skull (temple). A "thrust" should not be confused with a "strike" #대리기, which tends to reach its target with a curved or whipping trajectory.


The straight fingertip thrust as shown in the photos have the opposite palm below the elbow of the straightened arm. The palm-below-the elbow execution of the straight fingertip thrust is the formal way it is performed. This is not meant as a support for the arm. Rather, the palm is employed as a preliminary block. The palm is used to check the opponent's attack, to block down the opponent's attack, or push away the opponent's guard, in order to clear the path for the fingertip thrust. The block is formally taught as a palm downward block 손바닥 내려막기 (sonbadak nae-ryeo makgi) and as such the vector of the technique is downward. However, more advanced and realistic execution is as a type of parry, hence the block doesn't have to pedantically press down per se, but could instead just slap the opponent's attack aside (away from your center line), usually diagonally down rather than exactly downward. This deflection is very much akin to pak sao blocks in Wing Chun. As a strategy, this combination of clearing the obstacles followed by an instantaneous attack is very practical and can be done with other attacking tools. For instance, a palm downward block with simultaneous vertical punch, regular fore fist punch, or middle knuckle punch are obvious variation.


In the ITF Taekwon-Do curriculum, the straight fingertip thrust (with it's near instantaneous preliminary palm downward block) is taught around 8th geup as part of the fundamental movements in the pattern Do-San Teul (movement #6). Such a rapid combination of techniques is also found in another cluster in Do-San Teul, namely the fast motion double punch (movements #15 & #16 and #19 & #20).


Read more: Blocking in ITF Taekwon-Do