Techniques>Power>Hip snap-winding-sine wave-sawtooth

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Hip snap vs. winding vs. sine wave


Power comes from the hips, whether you are executing a hand technique or a foot technique. If your hip movement is loose, powerful, and quick, your techniques will have the same attributes. Martial arts, including the three versions of taekwondo (traditional, ITF, and WF), have different ways of using the hips to add power to techniques.

Hip rotation

When executing a stepping straight punch, as you push off the rear leg, both hips are pushed forward in a linear motion. If you let the push rotate the hips about the vertical center line of the body, the rotation will transfer some of the linear motion of the leg push into a rotational motion of the hips, which will add more power in the direction of the rotation. As the hips rotate, the torso and shoulders also rotate, all of which contribute to the overall power of the punch as the rotational motion is transferred into the linear motion of the punch. The linear and rotational forces of the body's mass combine to concentrate maximum power into a technique. To add even more rotational power to the hips, such as when executing a reverse punch, the heel of the pushing foot rises and the foot drives forward off the ball and toes.


To see the power that hip rotation adds to a technique, try this. Hold your lead arm in a hook punch position with the arm held shoulder high, arm parallel to the floor, elbow bent, and a horizontal fist pointed inward. Without moving the arm or shoulder muscles and keeping the torso tensed, hit a target with the fist by snapping the hips in a twisting/snapping motion to drive the fist into the target. Notice the "jolting" power with which the fist hits the target. Notice that, although not slow, the motion of the punch is not very quick.

Now strike the target with a hook punch motion that uses the arm, shoulder, and torso muscles without using any hip twist or snap. Notice the power is still great, but there is no jolting power. However, the punch is very quick.

Now strike the target while combining the two motions. Notice the quick, jolting power of the technique. If you had to get hit by a hook punch, which method of punching would you rather the attacker use?

Hip snap

Hip snap is not unique to taekwondo or karate; boxers have used it for over 70 years. Sam "The Tar Baby" Langsford told his young boxers to "get them hips into your punches" and Jack "The Manassas Mauler" Dempsey often referred to the importance of the waist twist when teaching his "shoulder whirl" technique.

Hip rotation is the driving force behind hand and leg techniques, but it is especially true for kicks. Many kicks, such as the crescent kick, are useless if the hips do not drive them. Always concentrate on hip movement during kicks and strikes.

In the Theory of Power section of his manual, Encyclopedia of Taekwon-Do, General Choi Hong Hi states that maximum kinetic energy of force is obtained from maximum mass and speed and that it’s important that the body mass is increased during the execution of a blow. He thinks that this may be accomplished by combining the hip rotation and the sine wave principle. As will be explained below, hip rotation adds to power, while the sine wave principle is based on false logic and not needed, and thus is wasted motion.

How to Perform Hip Snap

When performing the hip snap, think of the motion more as a delayed hip movement than as a rotation around the vertical axis of the body. For example, when stepping forward in a front stance with a straight punch, instead of thinking about hip snap as a rotation of the hip during the punch, think about the hip lagging behind the leg during the step and then suddenly snapping back into position just as the foot touches the floor.

Hip vibration

Hip vibration is a term used to describe the movement of the hip during the hip snap. The hip cocks, snaps forward, and recoils in short quick vibrating motion. The recoil part of the vibration serves as a counterbalancing motion, helping you maintain balance without over shifting the center of mass in the direction of the strike. Hip vibration is a subtle movement that takes hours and hours of training to perfect. The most common errors in the use of hip vibration are throwing the shoulders forward, not coordinating the timing of the hips and hands, and moving the hips too slowly.


What is winding? Winding, also known as knee spring, is a technique used in the International Taekwondo Federation (ITF) style punching. According to the ITF Theory of Power, to obtain maximum power there should be a forward and then downward momentum associated with a punch (Encyclopedia of Taekwon-Do, Vol. 2, p. 33, 38). Winding involves lifting the punching side heel prior to the punch (forward motion) and then dropping it (backward motion) as the punch is executed (Encyclopedia of Taekwon-Do, Vol. 3, p.16). The motion is sometimes accompanied by the upward circling of the punching arm as it is pulled back and thrust forward. When winding, the body moves slightly forward and then drops backward as a technique is fired.

Just as with the sine wave (examined below), winding requires some movement other than those related to the actual attack. Only an inexperienced fighter will cock a punch before throwing it. Although it may add power to the punch, it also adds time and it telegraphs intention to punch. Any motion that is not directly related to the actual attack wastes time and informs opponent of your intentions.

Sometimes, people accept some core belief and then search for justifications for the belief. In this search, they accept anything that sounds good and supports the theory, while rejecting anything that refutes the theory, even if it also sounds good. When evaluating any theory, not just martial arts theories, don’t except unsupported rationalizations. You don’t need a Ph.D. or a 10th-degree black belt, just use common sense and rational reasoning.

Sine wave

Most martial arts, including taekwondo, use a hip snap. However, the International Taekwondo Federation (ITF) also uses a movement it calls a “sine wave.” In the sine wave, the body rises as a technique is in transition and drops at the impact of the technique in an action called "knee spring." Although the sinewave the official way to move, not all ITF instructors support it.

General Hi created the sinewave movement and taught the sine wave as being an effective technique. He taught his instructors that it was an effective technique and they, in turn, taught their students that is was an effective technique. Over the years, all these ITF instructors, in an attempt to justify their use of the technique, have rationalized its use in taekwondo in spite of their being the only martial art to use it.

In his manual, General Hi, describes three types of waves: sine wave, horizontal wave, and sawtooth. In the sine wave, the center of mass follows an up and down motion along a curve that flows smoothly from one stance to the next. In the horizontal wave, the center of mass follows a straight-line movement with little up and down movement. In the sawtooth wave, the center of mass rises over a distance and then suddenly drops onto the stepping foot.

When performing straight punches from a sitting stance, hip snap practitioners use quick hip twists to add power by snapping body mass into the punch. The rotation is around the center of mass, but the center of mass doesn’t move vertically. Sinewave practitioners raise the center of mass and then drop it into the punch to supposedly add power. Snappers vibrate, wavers bob. Some taekwondo practitioners combine the two motions; they raise and cock the hip and then drop and snap it.

The sine wave motion is more apparent when viewed from the side. As a waver steps forward into a punch, the body rises during the first half of the step and drops during the second half of the step. Over a series of steps, the belt knot will appear to travel in a sine wave or a sawtooth motion.
Sine wave theorists posit that, as the body drops, its kinetic energy causes an increase in weight and speed and therefore, power. This is true, but to gain this kinetic energy, energy and time must be expended to raise the body to the increased height. The extra expended energy saps your energy reserves. The extra expended time slows your attack. Also, the sine wave motion adds extraneous movement to the attack. Any movement that is not toward the target is wasted. Also, as the body drops, it naturally drops toward the center of the earth, not forward into the target. To change this direction and make the drop move in the direction of the target requires more energy and creates a slower overall movement.

What goes up, must come down. Since the sine wave movement is up, then down, the end of the movement is at the down position, which must, therefore, be the normal, stable fighting position. Therefore, to attack, you must first rise to a position that is not as stable as the normal fighting position. This means you must commit to the attack before the actual attack occurs. What if the opponent acts in a way that makes the attack useless? You are now in an unstable position and your options are limited. With the hip snap, during the forward movement, you are always in a stable position, and the snap occurs at the same time as the attack. Thus, if the opponent acts in a way that makes the attack useless since there is no commitment to the attack, another attack or a block may be initiated.

For a body drop to add any significant energy to a technique, the body must have increased acceleration. Since the muscles can’t add other acceleration to the drop, the only acceleration that is added is that of the effect of gravity on the free-falling body. Since the distance of the fall is only a couple of inches, the acceleration is negligible. With the hip snap, muscles may be used to add significant acceleration and energy to a technique.

The sine wave motion telegraphs movement. For example, suppose you are in a fighting stance with your guard up, and the opponent watching your leading fist. If you execute a jab, what visual cues do you give the opponent that might tip him or her off to your attack? For a snapper, the opponent may notice that the body appears to be getting larger. At some point, the brain computes this to mean that the body is getting closer, but by then it is probably too late to react. For a waver, the fist body and then appears to get larger. The initial rise telegraphs the jab, giving the opponent a split-second more time to react. When the body rises, it is moving across the background, which the eye detects more quickly than a movement toward the eye.

Professional boxers make their living from punching opponents. If the sine wave movement was more effective, they would use it. Instead, they use a hip snap. They do bob and weave, but this is an avoidance movement, not an attack movement. Baseball hitters, golfers, tennis players, and disk golfers do not rise and then drop into their swing. They all use hip snap and hip rotation.

In a fighting stance, the knees are bent and ready to react. You never telegraph a movement by prepositioning the body. For an upward technique, such as a wedging block, as used in the to-san pattern, the knees drive upward without any initial downward movement. For a downward technique, such as a low outer forearm block, the knees drop into the block without any initial upward movement. For a jump kick, you jump without any downward movement. In any techniques, all movement should be toward the target. Any other movements telegraph the movement, waste vital energy reserves, and add extra time to the technique, all of which give the opponent more time to react.

Hip snapping is done without any initial movement. The hip is snapped from its location at the time the technique fires. Since it opposite hip is automatically cocked when the other hip snaps, it can add even more power to a follow-up technique from that side. The sine wave requires an initial movement upward.

Using the hips to apply power to a technique is a natural movement. If you tell the average person to push with the right hand, the right side of his or her body will twist into the push. The person will not rise and then drop into the push.

To test the difference between a hip snap and a sine wave, have a friend step into a sitting stance and extend his or her arm in a straight punch. Then you step into a sitting stance and move forward until the friend's fist is touching your chest. Then, without moving the fist, have your friend perform a sine wave bob into the fist. Di you feel a significant impact? Then have your friend perform a hip snap into the fist. Did you feel a significant increase in the impact?

General Hi, in the essential information section of his manual, states that in patterns:
  • Students should know the purpose of each movement.
  • Students should perform each movement with realism.

However, for a technique to be performed with realism, it should be:
  • Fast, so it may not be blocked. The sine wave adds extra movement and, thus, more time.
  • Focused, on target. Since there is up and down movement while punching, the punch is more difficult to focus.
  • Powerful, so it may do damage. As stated above, the hip snap adds more power.
  • Instinctive, so little thought is involved. Twisting the body into a punch is natural, bobbing up and down when punching is not.

Wavers view the sine wave as a natural walking motion. When we walk, we shift all our weight to the lead leg, step forward with the rear leg, and then shift our weight onto the new lead leg. The leg receiving the weight stays bent at the knee so there is very little up and down movement of the body and the forward weight shift is smooth. Some sine wave practitioners straighten the leg receiving the weight and suddenly bend it to drop the weight into the stepping leg in an abrupt, unnatural movement.

As I stated in other articles, a method of analyzing any technique or theory is to ask, if it so great, why don’t people use it. If you watch professionals, such as boxers, or martial artists or ordinary people spar or fight under stress when they are not consciously aware of their movements, they move naturally and usually don’t make unnatural movements. Untrained people may need instruction to help them eliminate bad habits and refine their movements, but they don’t need to learn unnatural ways of moving.

Patterns use exaggerated movements and strive for perfection in techniques, but they should not use any unnatural techniques. Sparring movements are basically the same as those used in patterns and they still strive for perfection of movement, but the movements are more concise for speed and they are focused and controlled so they don’t harm the opponent. Self-defense techniques are the same as used in patterns and sparring, except there is no concern for perfection and they are focused for maximum power and injury to the attacker. To be effective in pattern performance, sparring, or self-defense, we should use the same techniques and motions and not have to think about which to use in each situation.

When the public watches martial artists, or any other athletes perform, they see people performing smooth, rhythmic, natural movements. Sometimes the movements are performed to a level that only a highly trained athlete can perform, but the public doesn’t perceive the movements as unnatural. When the public, or a practitioner of any other style of martial arts, watches an ITF practitioner move in a sine wave motion, or especially in a sawtooth motion, the motion seems odd, contrived, and unnatural.

We move naturally, babies do not have to be taught how to move and walk, it just happens instinctively. World champion runners do not have to learn some new way of running, they just learn to perfect the movements of natural running. As martial artists, we need to perfect our techniques and move naturally. We don’t need to learn some new way of moving that some "master" as determined to be the best way to move, especially when it’s in opposition to the way nature has designed us to move. General Hi did a lot of things for taekwondo during his lifetime but inventing and teaching the sine wave and the sawtooth ways of moving were not one of them.

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