Kokyu ryoku as a result of Taijū no dendō

taïjū = body weight – dendō = transmission, conduction

Kokyū-Ryoku (呼吸力, Breath Power) Is the concept of relaxed power generated from the tanden. There is an implication in the word kokyū that this type of power does not clash with uke. (From Wikipedia)

Kokyu is mostly translated as “breath”, but can be understood as the concept of “prana” in yoga. Although it must be mentioned that breathing is only a small part of the prana concept also called “life force”. Breathing is a dynamic process and is an integral part of our being as a living person.

Another definition can be found in a a popular Japanese book:

Aikido: Tradition and Competitive Edge

In a book written by Tetsuro Nariyama and Fumiaki Shishida – Aikido: Tradition and Competitive Edge – Kokyu-ryoku and toitsuryoku is briefly mentioned. Correct use of the body and breathing can develop focused power: toitsuryoku. Some basic movements are explained to develop this kind of power. These exercises are very basic and you will find them also in other aiki-arts.

Don’t Think, Listen to the Body

Written by Akira Hino is an attempt to create a method to develop a martial body, useful in the many martial arts lacking an understandable method for developing soft power. This method is used as a supporting aid in our research.

An introduction into the practical use of opposing isometric tension

Taijū no ido & Taijū no dendō“, the relationship between the two concepts was discussed by using some Tomiki Aikidō techniques and/or exercises. The article is based upon a workshop we did some time ago. More explanations are needed to deepen the knowledge of these important concepts

In 2017 we made a short videoclip about “manipulation of structure”. At that time we were not aware about the importance of Taijū no ido & Taijū no dendō, and in particularity the use of Taijū no dendō concept. It was briefly mentioned, but the understanding was not so deep.

During Corona-Covid19 time , more people perform solo-training. Unfortunately the focus is mostly oriented upon the sequence and the outer appearance. Of course there are some on-line video clips with more information about the inner development during solo-training. There is perhaps one disadvantage with on-line teaching: no hands-on experience.

The example of bringing Taijū no dendō concept into the training has the same disadvantage: no hands-on experience. If you need this hands-on experience, find someone in the near future to solve your problem and give answers to your questions.

This post is an attempt to describe a solo-training pattern with words and some pictures. It is not the ideal format, but hopefully the near future will bring enlightenment.

There are “5 Steps” to consider in this kind of training

  • Step One: Awareness and moving bodyweight
  • Step Two: Stepping by using bodyweight
  • Step Three: Basic Tegatana movements without stepping
  • Step Four: Basic Tegatana movements with stepping
  • Step Five: Sotai dosa with integrated Taijū no dendō concept

First step in studying Taijū no dendō

Moving body weight

Body weight can move in 3 ways

  • Vertical plane
  • Horizontal plane
  • Combination of vertical and horizontal plane

Becoming aware of the bodyweight is the first step to explore the basic idea in Taijū no dendō. Body weight can move up and down. Imagine a structure as in the picture. Sometimes reference is made to tensegrity also called Jukozo, a term used in Japanese architecture for flexible structures.

Sometimes reference is made to tensegrity also called Jukozo, a term used in Japanese architecture for flexible structures.

Bodyweight can be put on different parts of the feet. During ritsuzen or standing exercises, bodyweight can change in all directions.

Bodyweight can move forward, backward or to the sides. Basically it can move following a 360° pattern. Keep the vertical line straight. Don’t disturb this line by bending the body forward for example. After some time practising, you will experience the vertical line in the body.

Second step

Ayumi ashi

Using the knees to transmit the bodyweight into the opponent is not by bending the knees, but by lowering the bodyweight which creates kneebending. Chidori-ashi walking is an exercise without a partner to learn how to move the body weight.

Another concept in the the training is the concept of “opposing isometric tension”. When the body weight is moving forward, the direction is going down into the front foot, in particular the ball of the foot. This creates opposing isometric tension. When lowering the body weight and the heel is touching the floor, the power of the opposing isometric tension is moving into the floor and makes your posture more stable.

  1. Start with a chidori ashi posture. Hand to the side. Bodyweight backwards.
  2. After turning the body, bring bodyweight forward and create opposing isometric tension.
  3. Put bodyweight more to the heel and release opposing isometric tension in the foot and leg. Koshi is lowering.
  4. Lift back foot and move it forward
  5. Assume chidori ashi posture.

Repeat this walking several times.

Third step

Tandoku undo (static exercise)

In the 3rd step we will introduce basic hand/arm movement based upon the “godosa tegatana” or 5 basic tegatana movements. Integrating koshi-mawari is necessary to create full body movement. Of course Taijū no dendō concept is a part of the movement. There is no stepping involved yet.

Although the exercises are primarly influenced by godosa tegatana, the first exercise is “shomen uchi” and is a basic movement with an origin in swordmanship. Basic tegatana movement, also called Tandoku Undo is a set developped by Kenji Tomiki and Hideo Ohba.

The use of opposing isometric tension is also a start for “hakkei” or explosive power. When the opposing isometric tension is guided into the floor, there will be a rebound and this can be directed into the hands. As a simple example “shomen uchi’ with isometric tension. Five basic tegatana movements use the same isometric tension method to produce “kokyu ryoku”, power generated by Taijū no dendō.

Fourth step

Tandoku undo (dynamic exercises)

Combining stepping and basic tegatana movements.

There are basically 2 methods of stepping:

  • Ayumi ashi: discussed earlier in this post – see Second Step
  • Tsugi ashi: using opposing isometric tension can create a sudden step forward full of power.

Shomen uchi with tsugi ashi

In Tomiki’s Aikido, Tandoku undo has a lot of versions. Most recent version use “shomen uchi” as the starting movement. Shomen uchi is a vertical downward strike to the head of an opponent. There is a relationship with a vertical strike with a sword (kiri oroshi). In koryu no kata daisan, tachi tai tachi, the first kata is ai-uchi or simultaneous strike. In many Japanese martial arts, a vertical strike belongs to the omote-waza or the first set of techniques/movements.

Fifth step

Sotai dosa

Using Taijū no dendō concept during paired exercises. An example can be seen at the beginning of this post.

How to use Taijū no dendō?

Using Taijū no dendō is already discussed in the 5 steps mentioned earlier. Sometimes it is necessary to step out of the box and introduce Taijū no dendō in another situation. Because we don’t have always a partner to experience bodily contact in real-time, we can mimic situations during solo-training.

For example, imagine someone is grasping your wrist and you like to apply balance disturbing with the gedan concept from 7-hon-no-kuzushi.

Taijū no dendō gedan

The turning of the hand can be used in aiki-age (upward movement or jodan) or aiki-sage (downward movement or gedan).

The turning point is in the palm of the hand. When using the wrist as a turning point, the line of power will be broken. An example with “gedan”.

The Switch

Changing the direction of power in a movement is not an easy task. We cannot interrupt the movement because is will also interrupt power generation. With every stop we have to start over again in generating power.
While your upper body muscles are directly involved with the action of the hand/arm, the force is generated throughout your body. Initial force is initiated by your lower body muscles and transferred through your core through to your upper body muscles. Any weakness or excessive tension in the transferring muscles will diminish the force and reduce performance.

6 major directions

We can move in many directions. Basically we consider 6 major directions. Other directions can be seen as a combination between 2 or 3 major directions and can become a spiral movement.
Movement can happen with the arms, the central body an/or the legs.

Switching between major directions

Switching is only possible when there is control of all the muscles involved.
An example how a switch can work can be more informative than words.

Kakae dori is an attack where an external pressure is applied to the body. Defending against such an attack needs a skill of expanding without using brute force.

If we allow the squeezing action of Uke, we will be thrown easily. If we can create a whole-body force against the squeezing, we will have the opportunity to free ourself. It is a question of using tension and relaxing at the same time. But how to do it?
It is based upon “opposing isometric force pairs”. There are of course other switching methods. If we suddenly, without any interuption, switch from outside tension to inside tension, uke may lose his grip and balance.

The exercise is to switch between internal and external pressure. The body needs to adapt to those 2 kinds of pressure images.

Push & pull vs. push-pull

Push&pull are two actions in a sequential order. Push-pull is one action. In the push-pull movement the balance between agonist and antagonist muscles creates a moving non-moving action. Push&pull or push-pull can be a straight line movement, a circular or a spiral movement.
When practising aikido or another martial art both action will be utilized to create attacking or defensive movements.
Again an example can be highly informative.

Push & pull

The first picture above is a push action into the ground, the second is the rebound of the power, the third picture is a pull action of the back foot bringing again close to the front foot to stabilize the equilibrium.


The first picture above is a push-pull action associated with holding a ball in the arm. Opposing isometric forces will move Uke around you.
The second picture is nearly a straight line push-pull. Although we said a straight line, the internal action relates to meguri. The meguri action is an internal spiral movement transmitted from the center of Tori to Uke through rotational movements of the hand/wrist/arm.The result will be a balance between a push-pull action. In other words an opposing isometric force.

Overlapping sequences

When we link all the singular movements of the body the result will be “rendo-movement”. During the performance of rendo movements, there are overlapping moments in the sequence of the actions. In the next example push & pull and push-pull are following a definite sequence.
But there is an overlapping between the different action in the sequence.

  • Picture1: grasping the arm
  • Picture2: pulling the arm
  • Picture3: body turn while keeping pulling
  • Picture4: keeping pulling and starting pushing
  • Picture5: keeping pulling and pushing while putting body into position to throw
  • Picture6: throwing and relaxing
Mae otoshi to gyaku gamae

Power needs some time to travel through the body, although this happens very fast. If we start too early our overlapping action, the force of the previous action will not be used to the full potential. If we start too late, the power of Rendo will be lost.

Tegatana dosa (tandoku undo) a switch exercise

Senta Yamada Tandoku Undo

These “tegatana dosa” are good examples to discuss switching the direction of force. As previously mentioned the mechanism of power generation:

While your upper body muscles are directly involved with the action of the hand/arm, the force is generated throughout your body. Initial force is initiated by your lower body muscles and transferred through your core through to your upper body muscles. Any weakness in the transferring muscles will diminish the force and reduce performance.

  • Uchi mawashi – Inside sweep

There are 4 arm actions in this exercise:

  • Turn the arm, palm hand up
  • Turn core of the body – tenshi
  • Switch the arm, palm hand down
  • Sweep the arm with body turn

If the exercise is done as 4 separate actions, there will be a reduced amount of power at the end of the movement. If the link between the 4 actions is established, there will be more power at the end of the movement. By using overlapping, performance will be more powerfull.

Using uchi mawashi in a paired exercise, proper unsoku (footwork) has to be added. Drilling the feet will increase efficiency.

Sotai dosa 3

In this example there is another concept which requires considiration.

We find Fibonacci Sequence at work in the principles, shapes, movements and strategies in nature but also within martial arts, by holding your arm with the correct angle at the elbow while extending your mind through the arm. The correct angle of human joints for movements has to be between 90* and 180°.

A push-pull and opposing isometric forces example
In the 7-hon-no-kuzushi gedan, spirals and opposing isometric forces are used to create balance disturbing. There are many variations, but basically all are build around spirals and opposing isometric forces.

we can see the Fibonacci spiral in combination with opposing isometric force pair. Uke will be fixed on the spot in an akward position.

  • Soto mawashi – Outside sweep

When using soto mawashi in partner training, some adaptations has to be done. The basic actions of uchi mawashi can be applied here too.

  • Turn the arm, palm hand up
  • Turn core of the body – tenshi
  • Switch the arm, palm hand up
  • Sweep the arm with body turn

Soto mawashi with partner after some adaptations.

  • Uchi gaeshi – soto gaeshi

In this sequence by Senta Yamada, the meguri concept is not visible. We only can guess if there is some internal movement invoking meguri.
In our research, the implementation of meguri and opposing isometric forces can increase the efficiency of these movement exponential. Switching the direction of forces is an aplication of meguri and opposing isometric forces and is needed to perform “waza” or techniques.

Opposing isometric forces

The human body as a movement construction is used by most of the people in a very inefficient way.
The body and mind are full of tension and this creates during a movement action sometimes a non-movement situation: a frozen action.
People think this can be resolved by relaxing the body and mind. Unfortunately relaxation is understood as a lack of tension resulting in collapsing body.
During a fight or in our case randori, we cannot have tension or relax. We need to find another solution based upon the concept “tone of the muscles”.

Balancing between tension and relaxing: Opposing Isometric Tension

Yi-quan* is a Chinese martial art famous for Zhang-zuang (Ritsuzen in Japanese) and the use of opposing isometric forces (zheng-li). Other Chinese martial arts are also using these concepts in a more or less manner during their training. The Japanese version of Yi-quan is called Taikiken and is utilizing many concepts borrowed from Yi-quan.
In Japanese Budo we certainly can find countless examples of “opposing isometric forces”.
Nobuyoshi Tamura**, an Aikido teacher used Baduajin or 8 brocade exercises as a tool to improve inner power. One of the concept in Baduajin is “opposing isometric forces”.

**I studied aikido during my early period (1970-1978) with Tamura sensei, Kanetsuka sensei, Kobayashi sensei – see also Intro
* I was introduced to Yiquan by Ilias Calimintzos (France)

Budo and opposing isometric forces

In Kodokan Judo there are many kata to explain the concepts of Kodokan Judo. One of the lesser known kata is “Go no kata”.
This kata has many “opposing isometric forces” to keep a power balance between Tori and Uke. It expresses very well the concept of “Go” as a counter concept of “Ju” found in “Ju no kata” and other Judo training tools.

Tomiki Aikido has many exercises to develop this kind of power. Even in other styles of aikido, this kind of exercises is frequenly used as mentioned in a previous paragraph.

Tomiki style opposing isometroc forces

From “Gendai Aiki”

Koichi Tohei famous unbendable arm can be classified in this category.

What are the thoughts of Kenji Tomiki on this matter?

Kono mondai wa, gendai taikugaku no, kinniku toreiningu no koto de, isometorikkusu to iun desu.
This is a matter of muscular training which is part of modern physical education. It’s called isometrics.

Sore wa, oshitari hiitari suru koto ni yotte, kukkin ya shinkin ga hataraku wake desu ga, jouzu ni naru to, kinniku ga hataraku no wa mienain desu.
That is to say, we can train inner or outer groups of muscles by pushing or pulling. A person who is highly skilled at this form of training hardly exhibits any muscle movement at all during the exercise.

見えないところで筋肉をうまく使えるんです。しかし、それ(このような理論を隠しておいて、大道の安芸人のようなことをすることをさす)を教育の場にもってきたら、非常に おかしい事になってしまうんです。
Mienai tokoro de kinniku wo umaku tsukaerun desu. Shikashi, sore (kono youna riron wo kakushite oite, oomichi no akibito no youna koto wo suru koto wo sasu) wo kouiku no ba ni motte kitara, hijouni okashii koto ni natte shimaun desu.
When you can’t see any movement the person is using his muscles very skillfully. But you are making a big mistake in the educational field if you demand a similar level of expertise from everyone.

Interview with Kenji Tomiki – Aiki News

Opposing isometric force pairs

The steering of a movement is the result of a neuro-muscular action. This action has 2 main components:

  • The use of internal and external factors: body and gravity
  • Using the mind as the manager of the internal and external factors

Movement of the body need always a support point and in most cases earth is the major support point. The mind is observing the body which is build according a vertical line in relationship with gravity. The mind is not interfering with this body action. Keep in your mind, standing is a movement.
Feeling with the feet the solidity of the earth, feeling the returning (rebound) power of gravity towards the head. Keep this stretch because this is the opposing isometric force by using gravity and correct body posture. Tanden (hara) plays an important role by becoming the center of the body. Gravity is always present even in non-vertical force lines.

Major opposing isometric force pairs are:

  • vertical line
  • left/right line
  • forward/backward line
  • diagonal line
  • combination of major lines

After developing major opposing isometric forces lines, the next step is to be applied them during movements. Keeping the isometric forces lines is a real challenge and we cannot expect an immediate result during training. Mind and body must become one and “ego” or “the monkey brain” ** cannot interfere with our movements, mentally or physically. Reaction to an attacking movement by an opponent must be handled by a spontaneous reflexive action.

**Taming the “Monkey Brain”
We all experienced the noise in our head when the monkey brain is talking during our exercises. Stopping thie noise is not a solution, because the monkey brain is not listening. Better is to ignore the noise, and after a while you will notice “the noice is gone”. You really start to feel the exercise and the dynamics of the body. This is forging the body and mind. It is not about bigger muscles, or more muscular strength. I can feel my body and its movements…..the rest is a side issue

How to develop opposing isometric force pairs

Opposing isometric force pair is a state of equilibrium between two tensions. If the two forces are equal, a balance is established between them.
This implies this form of tension inside the body which solicits two distinct zones. If we consider our body as a dynamic system, all types of force will involve the opposition of two forces regardless of direction.
For example, when you jump up, you use a force to hoist yourself up. You can also say that you exert a force down (ground).
To achieve upward movement, use the downward force. Similarly, to achieve a forward movement, it is necessary to exert the force towards the back.
We can interpret the function of the legs as that of spring which makes you bounce in height when you make a push towards the ground. This image speaks easily of the movement of legs that function as a pair of springs.
Let’s now look for the mobility of the trunk whose examination is fundamental to understand what an opposing isometric force pair is. The mobility of the trunk is not very visible, which makes it difficult to place the image of spring in relation to the movement of the legs. But the function of the trunk is crucial to organize the application system of the overall force of the body.
Like the springs of the legs, imagine that at the level of the sternum – kyokotsu – existed a spring that goes inwards to its antipode back. Following this example, let us situate imaginary springs inside the trunk to zones corresponding approximately to those of the chakras in yoga. These are in addition to the sternum, under the throat, plexus, navel and lower abdomen. All these springs are placed inside the trunk and their other end rests on the dorsal projection of these five points.
By putting the mind on the kyokotsu or other points of the body, we can move the kyokotsu in this example forward and back and use the image of the spring to create resistance.
The spring image can be internal, but can also have an external quality. If we use a spring connected between our elbows, we can open or close our arms and feel the resistance between the elbows.
A step further is to use the spring image between you and your training partner.

Developing spontaneous reflexive action

Reflexive action conditioning is primarily neuromuscular coordination training. You must have a firm foundation in multi-directional awareness before you can start this training. The goal is to achieve mind-intent and body action arriving simultaneously.
Internal movements during solo training can give an impression of “no movement” when there is no external movement visible. It is called “pause”. Posture training – ritsuzen – is mostly internal movement training wihout visible external big movements.
When doing moving exercises start always slow and use rather big movements.
Tegatana dosa, also called tandoku undo, are exercises to build this skill using the change between the different body (arm, hands,….) movements.
After many repetitions and using correct body movements with mind-intent leading the action, it will become a spontaneous reflexive action under control of the mind while maintaining the isometric tension.
Next step is to use these movements in paired exercises and all kinds of randori.