Power generation in (ITF) Taekwon-Do basically comes down to this:
accelerate as much body mass as possible in the direction of the technique, with emphasis on strong exhalation, and without compromising your balance and posture.
Relax
Try to always start from a relaxed position. This will require you to slightly and naturally bend your limbs. (You may find yourself somewhat lower than before.)
Your body motion might be described as going down.
Fall
One of the easiest ways to get as much body mass as possible accelerated is to merely “drop” your body. So momentarily forget that you have legs and just drop, letting your technique “fall” into your opponent with your whole body mass behind it. However, maintain control of your balance at all times. This method works great for techniques that go downwards or forwards at a slight downward angle. If you are already “up,” just fall. If you are low and still want to do a forward or downward type technique, then you will need to go up first and then fall into the technique. (If you are “low,” it might be better to use a technique that uses an upward angle, in which case follow the Push method.)
Your body motion might be describe as going down or up-down.
Push
We are assuming that your body is at a low position. For techniques that go upward or forwards at a slight upward angle, swiftly push with your legs up (and forward). If your body is “up” already, and you really want to do an upward-technique, it will obviously require you to come down first, then push up. (If you are “up” it might be better to just use a technique that uses a downward angle, in which case follow the Fall method.)
Your body motion might be described as going up, or down-up.
A good Taekwon-Doin knows how to "ride the wave" and will fall and push alternately, getting lots of body mass behind each technique.
Hip Rotation
Another way to accelerate body mass behind a technique is through rotating your torso by jerking your hips in the direction of the technique. It is usually possible to just jerk your hip in the direction of the technique from your current position, but sometimes you may need to pull your hip back first, then jerk it in the direction it has to go. Hip Rotation works very well for most techniques (you can use it both when falling and pushing to accelerate the fall or push), but it is especially effective for techniques that rotate sideways.
A very important part of Hip Rotation is to extend this principle through out the body into every limb and joint, so that each part of the body ads to the acceleration, creating a whip-like action. This is known as kinetic chaining or sequential motion.
Breath
Exhale during techniques, especially sharply at the moment your technique makes impact at which time you momentarily tense all your muscles. The exhalation should have the same feeling as when you naturally grunt while picking up a very heavy object.
These are the basics. Learn to fall, push and do whip-like rotation to maximise the acceleration of body mass behind a technique; also learn to relax, keep good balance, and exhale sharply, and you've got 80% of it nailed. The remainder is just some refinement, a better use of physics and body mechanics, and exploitation of your opponent's motions.
The ITF Taekwon-Do chief instructor, Sabeomnim Kim-Hoon, of The Way Martial Arts Academy of Seoul, the dojang where I practice at in Seoul, Korea, once said an intriguing thing: “The side-piercing kick is Taekwon-Do.” His statement is a shocking one considering that there are over a 100 kicks in ITF Taekwon-Do, probably more hand techniques and supposedly over 3000 technical combinations. Nonetheless, I intuitively felt the truth in his statement. Of all the techniques in ITF Taekwon-Do, there is probably no other technique that exemplifies this style as distinctly as the side-piercing kick.The kick is a wonderful combination of hard and soft, of linear and rotational forces. My first instructor, Sabeomnim Johan Bolton, used to say that it takes one around a decade to master the side-piercing kick. I've been practising it for more than 15 years and will not claim to have mastered it yet -- of course I'm much closer than I was a decade ago.
The first thing one notices about this ITF Taekwon-Do kick is that its name differ from other martial arts' reference to their similar kick. Most martial arts refer to it as a “side kick”. In ITF Taekwon-Do, however, it is called a “side-piercing kick.” Again as is the case with many technical terms translated into English, it is beneficial to look at the actual Korean term to better understand the technique. (See other posts that discuss Korean terms.) What is translated into English as “side-piercing kick” is in Korean yeobchajjireugi 엽차찌르기.
The first part, yeobcha 엽차, is short for yeobchagi 엽차기, which simply means side 엽 kick 차기. It is the rest, jjireugi 찌르기, which is curious. The term jjireugi 찌르기 is often only used in the martial arts and is usually tranlated into “punch” in English. For instance, front fore fist punch would be apjoomeok jjireugi 압주먹 찌르기. Jjireugi 찌르기 literally means to stab or pierce something, but in the Korean martial arts it has a very specific meaning. It refers to the uniquely martial art way of punching with the punching fist's palm facing up at the beginning of the punching motion and rotating on its way towards its target so that by the time the punch is completed the fist's palm is facing down. Laymen often refer to it as a Karate punch. Since it is found in many traditional martial arts we could probably refer to it as the traditional martial art punch or based on its characteristic motion, the rotational fist punch.
Now why would ITF Taekwon-Do's side kick have as part of its name this “piercing” or “rotational punching” part? In fact, when one looks at the term yeobchajjireugi 엽차찌르기, this rotational punching part is the main word, with yeobcha- 엽차- seemingly added as a prefix. From a purely semantic viewpoint it would seem that the most important part of the yeobchajjireugi 엽차찌르기 is the “piercing” / “rotational punching” part.
On another forum I was once asked why this should be the case; why is jjireugi 찌르기, the word always translated in Taekwon-Do as "punching," part of the name for Taekwon-Do's side kick? I can think of three possible answers.
It's just a long name
“Side piercing kick” is just a cumbersome way to say “side kick” and has no special significance.
I'm not an adherent of this theory because the terminology in Taekwon-Do, especially when one reads the Korean, is usually very specific and descriptive of how the technique is performed. General Choi Hong-Hi seemed to be very specific when he named the techniques and actually changed some traditional terms originally from Karate or traditional terms from Chinese into more technically clear terms.
It is a kick with a punch
One theory is that it is a kick with a punch. This theory has some legitimacy to it as anyone that knows ITF Taekwon-Do would know that one characteristic of the side-piercing kick is that the leading arm is often thrust out with the kick, as if one is kicking and punching at the same time. The reason we do that is not merely for the aesthetically pleasing parallel lines, there are functional reasons as well.
When performing a side kick, one's upper body is often left open, which can be exploited by a very tall opponent. This is something I've experienced on occasion while training with my friend Sabeomnim (Dr.) Garnet Ronander. During sparring training I would kick at him with a fully extended leg, yet he'd be able to lean over my kicking leg and still reach my head with a punch. By putting out the leading arm one creates a barrier between your upper body and possible attacks. It could possibly also act as an actual punch were your opponent able to push your kick down, at which point he would be met with your fist.
A second function for “punching” while doing a side kick is that it adds extra forward momentum. When doing a side kick one is often tempted to lean backwards; leaning backwards cause one to be less stable, which means you can be toppled easily if someone were to push hard against your kicking foot. Or because you don't have enough forward momentum your kick might “bounce” of its target. Thrusting out the punching arm helps with leaning your upper body forward more and thus adds more forward momentum, so that your kick have more penetrating force to the target, since more of your body mass is directed forward.
It's a kick that “punches”
Another theory, the one that I adhere to most, is that the side kick is performed like a punch; in other words, the side-piercing kick rotates in a straight line towards it's target in a similar way as a traditional martial arts punch rotates towards its target. The ITF Encyclopaedia explains that the "theory and purpose of this technique [is] similar to those of a punch" and that the "attacking tool must reach the target in a straight line with a revolving motion" (Volume 4, p. 25).
Seen from this point of view one can more easily distinguish between a side kick, as is often performed in Karate, and a side-piercing kick. In the traditional Karate side kick the kicking foot is kept horizontally and is snapped in an arcing fashion towards the target; hence it is often called a side snap kick. The video below shows a Karate side snap kick drill that clearly demonstrates the motion described. You will notice that the kick moves in an arc, not a straight line like a punch, and that the foot does not rotate.
You can see a better example of the Karate side kick in the VideoJug tutorial below. Carefully notice that the foot moves from below towards its target in an upward arc and therefore does not resemble the straight path of a rotational punch.
The Taekwon-Do side-piercing kick works differently.
Kickboxing master John Graden, known for his simplified teaching methods, describes how to perform a step side kick in the following tutorial video. His technique follows the Taekwon-Do method where the kick reaches the target in a straight line. Towards the end of the video he demonstrates part of the rotational force the Taekwon-Do side-piercing kick uses by pivoting the standing foot and so “roll the hip into the target.”
Master Graden's method, although closer to the ITF Taekwon-Do kick still doesn't demonstrate the real punching motion referred to in jjireugi 찌르기, but it does adhere to the "stabbing" or "piercing" idea.
I think the two tutorials below better demonstrate the Taekwon-Do side-piercing kick, particularly when the instructor demonstrates the kicks fast. The kick reaches the target in a relative perpendicular style. Also, when the kick is demonstrated fast, the kicking foot rotates towards the target in a “screwdriver” fashion. This pivoting of the standing foot helps with the rotation of the hip, which contributes rotational power (torque) to the technique.
The following video from a WTF source does a pretty good job at explaining how the kick's path should follow a straight line, and not an upward arc, nor jagged motion where the lower leg swings towards the target like a turning kick. Note that the way the master in this video demonstrates the kick is not how we do it in ITF. His kicks are swung towards the target in a turning kick fashion – the heel is not thrust straight towards the target. The young man in the video demonstrates the kick correctly.
By the way, I own theRevolution of Kicking DVDs from which the above video is sourced and although the kicks are based on WTF techniques, I can still recommend them to ITF practitioners, especially for the different strengthening exercises given for each kick.
In sumary:
The Korean phrase yeobchajjireugi 엽차찌르기, generally translated as side-piercing kick in English, is a combination of “side kick” and “stab” or “rotational punch.” The term probably refers to the way the kick is performed in Taekwon-Do. The kick reaches its target in a straight stabbing or traditional punching fashion. Extra force is provided by pivoting on the standing foot and so rotating the hip to add extra rotational power. In ITF Taekwon-Do the kick is often performed with the leading arm thrust outward in a punch-like action which could be a secondary reason for the name, which literally translates as side kick-stabbing or side kick-punching.
When we look at the sine wave motion in its typically down-up-down form we can identify it as a vertical* sine wave. With vertical I mean that the wave oscillates up and down. This motion is usually used in order to drop body weight onto the technique and works excellent for techniques with a slight or strong downward angle like a middle section punch or a side-fist downward strike. This sine wave motion can also be used in an upward direction; for example, when one does a forearm rising block you move from a relaxed position to an upward position. The final drop of the typical down-up-down motion is omitted as it will act contrary to the direction of the upward technique. The (vertical) sine wave motion is therefore employed for techniques where the force of the technique moves either up or down.
The sine wave can also occur horizontally*; in other words, the wave oscillates from left to right or vice-versa. Usually when we talk about this type of sine wave, we refer to hip rotation or hip twist. Typically the hip is pulled back slightly and then jerked in the direction that the blocking or attacking tool needs to travel. Hip rotation is often part of a whip-like action where the different parts of the body are accelerated and uncoiled to create kinetic chaining. Techniques that benefit from a horizontal wave typically move horizontally, for instance a back fist strike or a knife-hand side strike.
Do we combine (vertical) sine wave motion with hip rotation? Yes and no. It depends on the technique. A technique like a wedging block that uses two forearms moving horizontally in opposite directions do not use hip rotation because it is impossible to rotate your hips both left and right to accommodate both arms. For a wedging block we only use vertical sine wave motion. The forearm rising block is also a good example where the main force of the technique goes up; for this technique a horizontal wave, in other words hip rotation, is downplayed.
There are techniques where the main angle of the technique goes forward and downward and can therefore benefit from both the forward hip rotation as well as body dropping through the sine wave motion. A clear example would be a diagonal downward elbow strike (as seen the pattern Juche) or even just a forward stepping middle front punch. The middle front punch reaches its target in a slight downward angle. A further example is the low forearm block, which moves both downward and to the side.
Actually, the simple rotation of the fist during punching is in fact the combination of a vertical and horizontal sine wave. The rotation plus forward motion creates a spiral or helix, which can be described mathematically as the combination of a vertical and horizontal sine wave. These types of combined vertical and horizontal wave forms can often be seen in ITF Taekwon-Do by the trained eye.
The important thing is to understand the direction of the forces created by these waves and also the force directions required by the various techniques you are using. Certain techniques benefit more from a vertical sine wave, in other words the typical sine wave motion, while other techniques benefit more from a horizontal sine wave, in other words from hip rotation. Using or putting emphasis on the wrong wave form should be avoided as it may nullify the power of your technique. Also, different parts of the wave benefits different techniques. One should not drop your body weight at the end of a rising block, nor should you raise your body at the end of a low block. Similarly the hip should rotate towards the target, not away from it.
Learning how to use the different wave forms is crucial in mastering ITF Taekwon-Do.
* Please note that my reference to "vertical" and "horizontal" should not be confused with the use of these terms in the ITF Encyclopaedia's discussion on ways of stepping. I'm using the terms here to describe whether we are viewing a sine wave as depicted on a Y-axis (thus vertically) or Z-axis (thus horizontally).
Going through some of my old stuff I stumbled upon the following which I wrote for eSAITF a few years back. The "Whiplike-action" I speak of is a term I borrowed from Bruce Lee. The term I use now is Kinetic Chaining. Some people also speak of Sequential Motion. Regardless the terms used, they are in essence the same principle.
Whiplike-action for Power Generation
A very important principle I’ve witnessed in many martial arts, especially the Chinese arts, is the whip-like or coiled-spring action. This principle is apt also in Taekwon-Do. In this letter I thought merely to remind you all of this important power-generation method.
Bruce Lee [Footnote 1] describes this “method” as follows:
The whiplike or coiled-spring action of the human body in its striking (throwing) movement-pattern is a remarkable phenomenon. The movement of the body may start with a push of the toes, continue with a straightening of the knees and the trunk, add the shoulder rotation, the upper arm swing, and culminate in a forearm, wrist and finger snap. The timing is such that each segment adds its speed to that of the others. The shortened lever principle is used to accentuate many of the particular speeds of this uncoil or whip. The rotation of each segment around its particular join-fulcrum is made at high speed for that particular part; but each segment rate is accelerated tremendously because it rotates around a fulcrum already highly accelerated.
Although it is not so eloquently described in the ITF Encyclopaedia it is however suggested in some of the theoretical principles. For instance we read the following:
. . .It is very important that you should not unleash all your strength at the beginning but gradually. . .
. . .One is to concentrate every muscle of the body, particularly the bigger muscles around the hip and abdomen (which theoretically are slower than the smaller muscles of the other parts of the body) towards the appropriate tool to be used at the proper time. . .
. . .This is the reason why the hip and abdomen is jerked slightly before the hands and feet in any action. . .
. . .Thus the hip rotates in the same direction as that of the attacking or blocking tool. . .
. . .To bring the action of [everything] into one singe coordinated action. . .
. . .once the movement is in motion it should not be stopped before reaching the target. . .
I remember at one of my training session in preparation for 3rd degree with Master Kim Jong-Chol that he showed this with the blocking techniques. The upper-arm swings slightly before the forearm to add to the overall acceleration. And of course the actual blocking with the arms was prefigured by the stepping into a stance and the rotation of the hip [Footnote 2].
We use the same coiled-spring principle in our kicks. For example the front-snap starts by the slight jerk of the hip, the swing of the thigh and the snap of the lower leg.
Bruce Lee describes how to get the most acceleration using this uncoiling-method:
In throwing a ball, all the accumulated speeds of the body are present at the elbow when the forearm snaps over its fast-moving elbow-fulcrum. . . An important aspect of this multiple action of acceleration is the introduction of each segment movement as late as possible in order to take full advantage of the peak acceleration of its fulcrum. The arm is kept so far behind that the chest muscles pulling against it are tensed and stretched. The final wrist snap is postponed until the last instant before release or, in striking, before contact. In football, the punter puts the last snap into his knee and foot as, or a shade after, he makes contact with the ball. It is this last moment acceleration that is meant by ‘block through the man’ in football or ‘punch through the man’ in boxing. The principle is to preserve the maximum acceleration up to the last instant of contact. Regardless of distance, the final phase of a movement should be the fastest. Maintaining this increasing acceleration as long as there is contact is sound. . .
From this quote I hoped you also recognized other principle used in Taekwon-Do such as the principle of continuous acceleration (Speed), the heel-snap (knee-spring) at the end of the motion and striking beyond / through the target.
Some food for thought.
* Footnote 1:Quotes from Bruce Lee’s “The Tao of Jeet Kune Do”. There are a handful of crucial books that all martial artists should have in their library. If you don’t have this classic, I suggest you get it.
* Footnote 2: There is a trend in ITF to deemphasize the hip-rotation irrespective of the centrality it has in Taekwon-Do theory. Direct references to the turning of hip in the Theory of Power occur in both “Concentration” and “Mass” and can also be inferred from “Speed” as well as point 8 (“sine wave”) in the Training Secrets. The senior members of the Soo Shim Kwan decided that we will not follow the trend as the rotation of the hip is fundamental to Taekwon-Do theory. The Soo Shim Kwan acknowledges that we over-emphasized hip-rotation in the past. It was decided that over-emphasis will be avoided, but under-emphasis even more so.
In the previous post ("Double Hip") I mentioned how we in ITF Taekwon-Do pivot on the ball of the rear foot when rotating the hip for a reverse punch. I also mentioned how in Karate the foot is kept flat. In ITF Taekwon-Do the rotation starts in the foot, then the hip rotates, then the torso is pushed forward, then the shoulders, and finally the fist is flung forward. We call this sequential motion or kinetic chaining. The momentum of one part of the body is transferred to the next part of the body which continues the momentum to the next, until finally the attacking tool zaps to its target with the combined accumulated force of all the separate body parts.
Now look at a demonstration of the "gyaku zuki" (reverse punch) from Japanese Karate in the YouTube-video below:
Japanese Karate's "gyaku zuki" works differently from ITF Taekwon-Do's reverse punch. The rotation does not start from pivoting the foot, but starts from the hip. In fact, the rear foot pivots because of the extreme force working on it from above -- from the the big hip and torso rotation. Unlike the kinetic chaining in ITF Taekwon-Do where different parts of the body rotates, each adding to the momentum of the next in a sling shot fashion, the rotation in Japanese Karate does not seem to be sequential. If you look at the video again, notice that the hip, torso and arm rotates at the same time.
ITF Taekwon-Do has moved away from its Shotokan roots and has more in common, I believe, with some of the internal style Chinese martial arts and their concept of "fa jin."
Look at the video below of Tai-Chi Ch'uan Master Chen Xiaowang demonstrating "fa jin." Notice the alternation between relaxation and then sudden acceleration. This is known among the internal or soft style Chinese martial arts as "fa jin." This type of relaxation flowing into explosive acceleration using kinetic chaining is in fact the same thing we do in ITF Taekwon-Do. If you do not recognise the similarity then it probably means that you are focussing to much on vertical sine wave in your technique and too little on horizontal wave, i.e. kinetic chaining.
As far as horizontal body rotation is concerned, I believe that power generation in ITF Taekwon-Do is closer to Tai-Chi Ch'uan than Japanese Karate. Historically Taekwon-Do movements were very linear, resembling its Shotokan Karate roots. We can still see it in old style Taekwon-Do -- those schools that went independent of the ITF before the 1980s. Current ITF Taekwon-Do focus a lot on relaxation and various circular movements. For instance, when punching in Taekwon-Do the arm is not pulled to the hip, momentarily resting there, and then thrust again straight to the target. Instead, the arm is pulled back, but instead of stopping it does a small elliptical motion before thrusting out to the target. These ellipsis and circles that have become part of ITF Taekwon-Do has its cause in at least two maxims we adhere to in ITF Taekwon-Do:
1. The limbs should stay slightly bend (i.e. relaxed) through out its motion until it reaches its target.
2. The movement should never stop, until it reaches its target. (No jerky motions. No pulling back, stopping, then striking.)
The (sine) wave principle is one way we use to implement these maxims and create kinetic chaining. The wave helps us to stay relaxed and, if done correctly, prevents jerky (saw tooth type) movements.
In the video below Coach Moore, an MMA instructor, is experimenting with what I would like to call a horizontal (sine) wave motion with the hip. The renowned self-defence instructor Peter Conserdine is known for teaching this "double hip" punch. It is not his own invention; rather, it is a rediscovery of an old Karate technique. We do something similar in ITF Taekwon-Do and usually refer to it as "hip rotation" or "hip jerk." It derives from the section on "Mass" in ITF Taekwon-Do's Theory of Power.
While watching the video, notice Coach Moore's legs. Particularly notice how he bends the front knee, lifts the back heel of the ground, and then slams the back heel back to the floor at the end of the technique to absorb any rebound energy. This is practically the same mechanics we employ in ITF Taekwon-Do when we do our peculiar "sine wave motion." Notice the similar mechanics between what he is doing and what we do when perform, what is sometimes known as, the "D"-formation -- i.e. the rolling of the knees, the lifting of the body in a slight arc, and then the drop of the body while thrusting the hip forward.
Of course it is not exactly the same, but there are similarities. Particularly as far as the horizontal wave, in other words, the hip rotation is concerned; although in recent years we do not perform such an exaggerated hip rotation any more. We often find ourselves with one hip already in a forward position and therefore negating the need for a "double hip" as Coach Moore is demonstrating in the video. Usually we are standing in a guarded position or in a blocking posture, which requires that we be "half facing" the opponent; this means that one hip is already rotated forward. To do a reverse punch from such a position we merely need to thrust the opposite -- rear -- hip forward. Attempting a "double hip" when the hips are not squared, when one is already pulled back, would just waste time. Coach Moore, on the other hand, is not starting off in a half facing position. He starts off full facing -- hips squared, face forward -- and then as he starts the punch (by rolling the front knee) he turns in to a half facing. This causes the leading hip to thrust forward, then followed by thrusting the rear hip forward -- hence the name "double hip" punch.
The principle is in effect the same as we do in ITF Taekwon-Do. The way he rolls his knees are also similar to what we achieve with our sine wave motion. However, in ITF Taekwon-Do we would not swivel the front knee as much. We tend to roll the knee in a vertical circle -- forward, up, and down; we do not rotate the knee horizontally as much. Our hip thrust is also a little less. Peter Conserdine's method creates actually more forward thrust, I believe, but it also creates lots of side ways forces that my hamper ones balance, especially when stepping forward. It would be very difficult to do the "double hip" punch as Coach Moore is demonstrating while stepping forward. For this reason we tone down the technique somewhat in ITF Taekwon-Do. Although we do lose some of the power, we keep more of our dynamic balance, which is very important for stepping.
What I'd like to point out in this post is that the mechanics of the sine wave motion does not merely contributed to vertical forces -- in other words dropping the body weight behind a punch -- but also contributes to the horizontal force of hip rotation. Both requires a rolling of the knees. What we cannot see in the video clearly is what he is doing with his back heel, but one can deduce some things. We know that he is lifting up the back heel. This means that he is pivoting on the ball of his foot as he is thrusting his rear hip forward. We do the same thing in ITF Taekwon-Do -- never do we pivot the rear foot while it's completely flat on the ground, as this puts a lot of strain on the knee joint. In this way we are different from many Karate systems which will actually keep the back foot flat, while rotating the hips; a potentially unsafe practise. One of my friends (she used to be a Karateka) has injured her knees this way.
Look at this video of a baseball pitcher. The principles employed are practically the same that ITF Taekwon-Do requires of its practitioners – although more subdued.
First, notice how the pitcher throws his body weight down and forward. This is what we would call the sine wave motion, going from a high position to a lowered position.
The other thing to notice is how he uses kinetic chaining, also known as sequential motion – usually and simplistically explained as “hip rotation.” The pitcher torques his body, starting from the legs, then the hips, through the spine and shoulders, and last whipping through the arm. The momentum of each segment of the body contributes to the momentum of the next part of the body.
Of course, the martial art practitioner needs to subdue such an over exaggerated motion because it exposes you at various moments throughout the motion, compromise your posture and somewhat unbalance you at the end. When the Taekwon-Do practitioner is admonished to keep the back heel flat at the end of the technique and to square the shoulders, it is in fact to ensure better posture and keep the rebound energy from not unbalancing the performer.
Now look at Randy Barnes perform a shot put. Notice how the same two power generating principles are evident, a sine wave motion and kinetic chaining. Look at the slow motion section starting at 1:00 and note how his vertical movement goes down, up and down (this is where we will punch); however, from here he is pushing the iron ball at an upward angle, so he needs to thrust his body up again. (During the entirety of his technique Barnes moves down-up-down-up.)
There aren’t any hand strikes that require us to do two rotations like Randy Barnes does for his shot put. We do have a spinning back fist strike that requires one rotation; take for instance the spinning back fist strike in the pattern Do-San, which follows the spear fingertip thrust and release (movements #6-8).
The two principles of dropping your raised body mass into your technique and using kinetic chaining / sequential motion are present in many sports concerned with speed and power generation.
