Introduction:
Each person who begins training in karate may do so for a specific reason, or for a combination of reasons. Some people train to learn self-defense. Some people train for health reasons. Some people train because “I saw this person do these really cool things in that movie (or TV show) and I want to learn to do that!” Regardless of the student’s motivations we, as teachers, strive to pass on our knowledge of karate to the best of our abilities.
We teach the proper body mechanics to block, punch, strike, kick, sweep, throw, etc. Body mechanics are the kinetic chain that travels through the feet, legs, hips, chest, shoulders, arms, and head required to deliver a punch, strike, kick, sweep, throw, etc. We can refer to all of this as teaching the fundamentals of karate.
As expressed by Mike Foster 1 we, as teachers, need to make sure our students have the technical ability to fight. One aspect of that technical ability is generating power in karate techniques. So, what is power and how do we generate power in karate?
What is Power?
Power can be expressed as Work (or Force) / Time 2. In karate we think of power as the strength, or force behind a technique 3.
To deliver proper techniques there are four fundamentals required in karate – good posture, good structural alignment, good body mechanics and good practical functionality (ie: distance, timing, application of techniques, etc) 4.
Assuming we have, and our students are learning, good posture, good structural alignment, good body mechanics and good practical functionality, how do we generate power in our techniques?
How do we generate power in karate?
There are three methods of generating power in karate – hip rotation, moving the center of gravity to create momentum, and speed. Sometimes these methods are used in isolation, many times these methods are used together to create a “kinetic chain” to transfer power into our techniques.
- Hip rotation
In karate (and in many other physical activities such as baseball or golf) we use the term “hip rotation” to describe pelvis rotation. To illustrate, stand with your feet shoulder width apart and arms relaxed at your sides. Your chest is facing forward.
Without moving your feet or your knees push your right pelvis forward and pull your left pelvis backward, allowing your shoulders to follow the movement of your torso. Without any other movement of your feet or knees your torso will stop with your right shoulder forward and your left shoulder back, and your chest will be facing about 45 degrees left of center.
Now, move your left pelvis forward and pull your right pelvis backward until your left shoulder is forward and your right shoulder is back, and your chest will be facing about 45 degrees right of center.
This exercise demonstrates the range of motion of pelvis rotation. In karate we call this “moving your hips”.
This “hip rotation” transfers the rotation up through your torso, through your shoulder girdle, and (assuming you are punching) through your arm to your target. The faster, more explosive the hip rotation, the more rotational force is transferred through your torso, shoulders and arms.
As Masatoshi Nakayama said in his book Dynamic Karate, “The destructive force of karate is generated by turning the body, and especially by rotating the hips. In delivering a karate punch, just as in hitting a baseball or golf ball, the smooth, swift, and level turn of the hips is essential to the effective application of power. You cannot throw an effective punch with arm and shoulder strength alone.” 5
Yoshukai Karate has lots of examples in kata whereby a technique is executed with power via hip rotation. A few examples of generating power through hip rotation in our kata are (note – once access is obtained to the dropbox storage account with our written kata the counts below will be verified):
Hip Rotation
27 Movements – count #s 10 & 11 – choku zuki or straight punches
Zenshinkotai – count # 11 – the three middle punches in Yoi stance
Zenshinkotai – count #s 6 & 8 – gyaku zuki or reverse punch
Zenshinkotai – count #s 6 & 8 front hand punch (following the reverse punch)
Seisan – count # 2 – gyaku zuki or reverse punch
These are certainly not the only kata where hip rotation is used to generate power for particular techniques, and certainly not the only moves in 27 Movements, Zenshinkotai or Seisan that use hip rotation.
- Moving the Center of Gravity to create Momentum – Shifting Body Weight
The next method for generating power is learning to shift body weight – moving your center of gravity to create momentum.
“Gravity is the downward pull or force that the earth exerts on your body” 6. With the human body, the center of gravity is the point within your body around which gravity seems to act. As you move your limbs and torso your center of gravity changes.
To illustrate, walk forwards several steps. As you move forward your center of gravity moves, and your feet step forward (with counter-balancing arm swings) to maintain your balance and posture as you walk. If you continued to walk forward until you collided with a wall, the force of that collision would depend on your body mass, how fast you were walking, etc. If you were running forward instead of walking, and, again, collided with a wall, the force of that collision would be greater than the force of the collision when you were walking (since the same mass was moving faster when running).
We move our center of gravity in Yoshukai Karate whenever we take a step or shift our weight from one foot to the other foot. By moving our center of gravity, we create momentum which can add power to our techniques. In karate it is vital to shift the center of gravity correctly, especially when performing a series of movements in sequence. 7
Whether a technique is performed in isolation or in a series (as in kata) this shifting of the body’s weight – the center of gravity – can be forwards, backwards, sideways, upwards, downwards, or angular 8.
Forward Momentum
To illustrate forward momentum step forward into a right front stance, then execute a right-hand center punch. Your center of gravity moved forward until you completed your step, but all forward momentum stopped once your front foot stopped. You can generate power for your punch now with hip rotation, but you didn’t generate power from our forward momentum.
Next, step forward into a right front stance, but finish the right-hand center punch (impacting the target) a picosecond before your front foot plants. The momentum generated by the forward shift of your center of gravity (moving forward to a front stance) will be transmitted into the target. This second example is more powerful than the first because it includes momentum to generate power 9, 10.
Examples in kata where a technique is executed with power via forward momentum:
Zenshinkotai – count #s 1 & 2 – step forward lunge punch – your weight moves forward into your lunge punch
Rohai Sho & Rohai Dai – count # 8 –stepping lunge punches (renzoku tsuki) – this is an example of continuing your forward momentum, driving your target with your first punch and continuing to drive your weight into your second punch.
Backward Momentum
Backward momentum is momentum gained by shifting your weight back. Think of this as a pulling motion.
Examples in kata where a technique is executed with power via backward momentum:
Gega Sai – counts # 14 & 16 – step back while grabbing with both hands, pulling to your left or right hip.
Niseishi – counts # 13 & 16 – step back and pull both hands up and back to the back shoulder
Seisan – count # 29 – step back while grabbing with left hand, pulling left elbow to ribs
Angular Momentum
Think of Angular Momentum as rotational momentum – momentum gained by rotating your body (not just your hips).
Examples of Angular Momentum in kata:
Shihohai– count # 1 – your body pivots on your left foot as your body weight rotates forward and to the left at a 90-degree angle.
H Forms – count # 3, count # 9 (any of the turns) – pivoting your body as your weight rotates to generate power for the end of the technique or for a throw.
Sanshi Ryu – count # 8 – arms sweep up to the left, then torso rotates 180 degrees to the left as stance transitions from shiko dachi to kosa dachi as arms sweep down to the left for a throw or block.
Weight Drop
A Weight Drop is when you generate power by dropping your weight (lowering your center of gravity) in a technique.
Examples of Weight Drop in kata:
Zenshinkotai – count # 10 – after the left down block and left side kick – middle punch as left leg drops to Yoi stance.
H-Forms – count # 1 – center of gravity drops slightly as stance shifts from Yoi stance to front stance
Rohai Sho & Rohai Dai – count # 1 – dropping your weight into your right knee (on top of an opponent lying on the ground).
Tenshin – #s 6 & 21 – morote yoko gedan barai while the left foot drops into shiko dachi
Sanshi Ryu – count # 1 (double down blocks as heels rotate out (which lowers your center of gravity slightly)
Weight lift
A Weight Lift is when you generate power by an upward shift of your weight (center of gravity).
Examples of Weight Lift in kata:
Chinto – count # 19 – driving up from the floor with morote tsuki.
Sanshi Ryu – count # 1 -heels rotate in, which raises your center of gravity slightly as you execute double inside center blocks (hands open)
Ryu San – count # 10 – weight drives up as left knee straightens in ippon dachi and left palm drives up
Assuming we have good posture, good structural alignment, and good body mechanics as we engage our hips and/or shifting of our body weight to generate power, is there any other element needed to maximize the amount of power generated? What is the last piece driving the kinetic chain?
- Speed
Speed is the final piece of the power formula. Remember power is defined as Work (or force) / time. Since time is the numerator is this formula, the shorter the time duration (the faster the duration) the greater the power (assuming “work” or “force” remained the same).
Speed is the measure of time an object travels a certain distance.
As an illustration get in a fighting posture and have someone hold up an open hand, palm towards you, as a target. Without moving your feet, extend a jab slowly, so it takes 3 seconds from beginning to end (when you contact the target). Retract your jab. This time, extend the jab a little faster, so it takes 1 second from beginning to end (impact). Retract your jab. This time, extend the jab faster, so it takes ½ second from beginning to end (impact). For the last jab, extend the jab as fast as you can till impact.
You and your partner should both feel that the faster the jab the harder the impact 11. The faster the speed the more power 12. To paraphrase a quote from Bruce Lee – a powerful karateka is not a strong karateka but is a karateka that can exert his strength quickly, or with speed 13. All other factors being equal, the greater the speed a technique is executed the greater the power 14.
Conclusion:
Regardless of the specific reason or reasons a person begins training in karate we, as teachers, strive to teach them the fundamentals of Yoshukai Karate – to deliver a punch, strike, kick, sweep, throw, etc, with speed, efficiency, effectiveness, timing, and power.
To teach students to apply power in their kihon, kata and kumite we need to recognize and teach the three methods of generating power in karate – hip rotation, moving the center of gravity to create momentum, and speed. As stated above sometimes one of these methods is used in isolation to generate power. However, many times in our kihon, kata and kumite these methods are used together, creating a “kinetic chain” to transfer power into our techniques.
We need to continually practice these points and teach them to our students so we can embody the meaning of Yoshukai – the Training Hall of Continuing Development and Improvement.
Bibliography:
- From my personal notes from Summer Camp, 6/30/1989 – 7/02/1989.
- https://www.physicsclassroom.com/class/energy/Lesson-1/Power
- www.royalwestmartialarts.com/theory-of-power
- Karate Science, by J.D. Swanson, PHD, pages 11-15.
- Dynamic Karate by Masatoshi Nakayama, page 57.
- www.physio-pedia.com/Centre of Gravity.
- Karate The Art of “Empty-Hand” Fighting, Hidetaka Nishiyama and Richard C Brown, page 148.
- Karate Science, by J.D. Swanson, PHD, page 142.
- Dynamic Karate by Masatoshi Nakayama, page 114.
- Karate The Art of “Empty-Hand” Fighting, Hidetaka Nishiyama and Richard C Brown, page 74.
- Biomechanics for Dummies, Steve McCaw, page 131
- Dynamic Karate by Masatoshi Nakayama, page 16.
- Dynamic Karate by Masatoshi Nakayama, page 16.
- Tao of Jeet Kune Do, Expanded Edition by Bruce Lee, page 47.
