Rendo -The art of linking

A “martial art body” is determined by the word “Jukozo” or flexible structure.
When we see how someone is catching a ball, we can get an idea how the body works during a whole body movement.

The synchronisation of the body with the ball is the main concept. Catching with a stiff body will not be very successful in catching the ball.

Developing a flexible structure – Jukozo

This has nothing to do with stretching exercises per se; rather, it has to do with learning to maintain a certain suppleness and adjustability in the body.
By controlling different parts of the body, we can create linked movement segments. The power of Rendo is going further than the power of an isolated movement of the arm.

We can move the arm or we can move the arm as a whole body movement.

Isolated movement = Movement segment

From a scientific point of view, a movement segment is “a functional unit made up of two adjacent articulating surfaces and the connecting tissues binding them together. “

This is for most of us too difficult to understand, we need a more simple and practiacal explanation.

The green dots are 3 centres to create a stable posture.

The yellow dots show the movement segment of the arm.

The red dots show the movement segment of the leg.

Of course, this is very simplified, but it has some practical use for our training.

Whole body movement

Whole body movement is made by linking movement and postural segments and it is called “rendo”. It is not only a physical action, the brain (and its functions) plays also an important role.

Postural Segment

Once again, simplicity is key to success in an entire body movement. Too many details create a malfunction in our brain. Also, understand that there are more than 3 points required to move an arm (or other segment) efficiently. Maybe one time you will feel so many dots that it becomes a flow. Each point during the movement can be handled by your mind… the game of “ki” begins.

Of course, it is not easy to control the linking process. Controlling the mind using “zanshin” or focusing the mind may be the first step of the control process. Zanshin is a skill how to use the mind to control our body and movements. Many martial traditions mention this skill and use the art of standing – Ritsuzen – (ZhanZuang in Chinese arts) to perfect the focusing skill. Ritsuzen is a simplistic method to create Jukozo. Ritsuzen uses three main areas of his body:

  • The Mind residing in the head
  • Sternum
  • Pelvic region

In our research on martial arts training, most methods mention vertical posture as the most favourable to apply a punch or strike to the opponent. Even when working at the office, the upright posture is the healthiest.

Let us examine these centres and begin with the centre of the basin, the pelvic area or hara.

Hara, the pelvic region

The word “hara” is often used to describe the use of power in martial arts training.

Hara can be described either as the physical centre of a human being or as the metaphysical centre.

As part of our training, the hara may be considered the physical centre and it contains the centre of gravity. This is true in most cases, because it is possible that the centre of gravity is somewhere outside our body. The centre of gravity is not fixed in any particular place.

If you’re doing an Internet search, there’s a lot of information out there. And some of this info can be helpful during our training.

  • The balancing, equilibrium, or pivoting point of the body. 
  • It is the point where the sum of all the forces and force  movements acting on the body is zero. 
  • It is the point at which all the weight of the body may be  considered to be concentrated and about which all the  parts exactly balance.

A physical view

When standing, the centre of gravity in the human body is located in the front of the sacrum at the height of the sacral vertebras.

A metaphysical view on hara

In our western culture, the pelvic region has still a kind of taboo. The association with our sex organs makes it difficult to talk about this region. From a metaphysical point of view, the pelvic region is a source of energy. When you have an interest in this matter, I suggest you to look into the many articles on the internet on Traditional Eastern Medicine and Healthy Living.

So, please put aside your taboo thinking and see our pelvic region as an important part of whole body movement.

Kyokotsu, the sternum centre

Like the hara, kyokotsu is a small part of the body which cannot be regarded as a hinge. Basically, it cannot move by itself. Nevertheless, with the help of the surrounding muscles, it is mobile and will affect the spinal column and the attached muscles. Since the spinal cord is involved, it will also influence the use of the hara or pelvic region.

Movements of the arm is not only by using local arm muscles, but it is a process of a whole body movement. By controlling kyokotsu, we can use the muscles of the pelvic region and the attached legs.

Connection between hand and kyokotsu is by determining the “dots” between root, segment and tip.

The Mind

The function of ‘The Mind” is briefly described in another post: “The science of training”.

Previously I mentioned Zanshin or controlling the mind to perfect the skill of focusing the mind. It takes a lot of training time to become skilful and maybe this goes beyond too much the motivation to do a martial art. If you go this path, you cannot ignore the metaphysical part of training.

Many martial sport champions acknowledge the importance of this part of the training. Controlling the mind is a basic skill to create high competence in your art. And this applies also for all sports or professional activities.

On the other hand, if your martial art activity is some kind of social gathering with friends, this is not a mistake but don’t expect a high level performance. Martial arts have different faces, and you can make a choice.

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”.