Kuzushi – A figure 8 question

Bertrand Russell once said, “Mathematics is the subject in which we never know what we are talking about nor whether what we say is true.
During the eighteenth and nineteenth centuries, mathematical problems were discussed in societies and solutions were almost formulated according to religious beliefs and axioms. Mathematicians from this period assumed that axioms are true without being able to prove them. In certain societies, mathematics were an intellectual game to show superiority to ordinary people.

Some martial arts are also based upon religious or mystical beliefs. Some are invented as an intellectual tangle that needed a certain belief of unproven facts about our origin of life.
Basically, there’s nothing wrong with those axioms as long as they don’t stop you from being creative.

Follow the rules, but don’t let the rules controlling you

Breaking the balance, upsetting the balance or kuzushi is a concept that should follow certain rules. If the concept turns into an intellectual game, the application is not always useful in training or randori. Sometimes people adapt to the circumstances of randori in favor of the intellectual ideas. Basically, it is cheating by creating an illusion of effectiveness based on an intellectual tangle that is useless in a confrontation with someone who does not follow the rules.

Kuzushi

The noun comes from the transitive verb kuzusu (崩す), meaning to level, pull down, destroy or demolish. As such, it refers to not just an unbalancing, but the process of putting an opponent to a position, where stability, and hence the ability to regain uncompromised balance for attacking, is destroyed.

Wikipedia

There are many examples to explain the skill of balance breaking – kuzushi. A famous picture used by Kodokan Judo explaining “minimum effort, maximum efficiency”.
A body out of balance can be easily manipulated.

Cardinal and inter-cardinal directions

Cardinal directions are an interesting concept because practically every culture on Earth has independently used them or something analogous to them, from Chinese ancient cultures to European and Arabic cultures, to Aboriginal Australia….

Cardinal directions are a concept that can be used strategically in martial arts to define the direction we move during footwork or when we use power.
The four cardinal directions are merely labels used to describe the specific directions of force and movement. The 4 directions are complemented by intersectional directions.
Tomiki Aikido or Shodokan Aïkido, both as a symbol using cardinal directions.

Origin of the Nihon Aikido Association symbol

“Ten no Maki” (Book of the Heaven) of the Kitoryu jujitsu says: “Being upright is the yang form, being prone is the yin form. Win by the yang, win by the yin. The feeble seizes the strong, the flexibility seizes the stiffness.”

Being upright stands for power of fire, being prone stands for power of water. The sun is the source of the energies, while water has no form or intent, and obliges the environment. At the same time its might excels that of anything. It enhances growth of all entities, and does not try to gain position higher than its place.
Such are the might as the ultimate morality. Thus the saying goes “superior virtue is like the water”.
The symbol is composed of the function of water and fire, and the whitenis signifies the infinite space.

The Cardinal Directions concept is often compared to an eight point compass with the cardinal directions and the inter-cardinal directions called “corners”.

To make it simple, when we mention Cardinal Directions, the corners are included.

Kuzushi and the Cardinal Directions

Kuzushi is part of the training and the structured process is required to explain the technical details and applications. But sometimes people are too focused on the structured method and forget what kuzushi is all about: preparing for other applications.
Kodokan Judo uses a cardinal direction structure to explain Kuzushi.

Probably one of the most famous pictures on kuzushi. It is used to give a visual idea about kuzushi in Kodokan Judo.

A website for traditonal aikido transformed the Kodokan Judo Kuzushi in an Aikido related kind of kuzushi.

The 8 positions of the elbow

The structure of the cardinal directions of Tomiki Aikido related to the position of the elbow.

Tegatana, a tool for kuzushi

Some historical facts on kuzushi in Tomiki’s Aikido
In about 1958, students practiced mainly the unsoku, tandoku undo, yonhon no kuzushi (chudan and gedan). In around 1960, the roppon no kuzushi/6-hon no kuzushi were created (jodan, chudan and gedan). In the mid-sixties, Koryu no kata was created. There are 6 koryu no kata and especially number 4 is focused on the use of tegatana as a tool for kuzushi.

The JAA (Japan Aikido Association) published in 2009 “Competitive Aikido” an introduction to practices leading from kata to randori.
Kuzushi is explained with the principles of the sword (tegatana dosa).


Main idea of kuzushi is focusing on position of opponent’s elbow – up or down.

On mobility and stability

Mobility -Mobility allows a person to move with no restrictions. It can often be confused with flexibility, but flexibility does not always mean good mobility. Although the person has good flexibility, they may not have the force, coordination or balance to perform the required movement.

Stability – Mobility is linked to motion, while stability is linked to control. Stability may be defined as the ability to remain in control.

We need these two skills to carry out our movements effectively. And as with most skills, we need continuous training to keep our mind and body in the optimal state of mobility with high stability.
Using the mind in your workout, the body will benefit much more than just training on autopilot. Of course, there must be harmony between mind and body and the ability of “stillness” is necessary.

What is “Stillness”?

An absence of motion or sound. That’s what you’ll find if you do a quick search on the Internet. Of course, it goes much further, but in case of martial art practice the concept of “mushin mugamae” comes forward.

“Stillness in Motion” & “Motion in Stillness”

There are 2 kinds of motion:

  • Internal movement – movement centralized around the center of the body
  • External movement – movement expressed by arms or legs

Both movement work together to create whole body movement.

Seichusen or the central human pilar
The concept of “Stillness in Motion” and “Motion in Stillness” means that while the mind is calm, necessary actions are already in motion. This can be demonstrated as an expanding circle, the center of the circle does not move, it only turns. The training partner will move around. The radius of the circle can expand if necessary.

The mind is a crucial factor in the training. If you are angry, your body will show your mind. If your mind cannot let go your anger or frustration, your body will tense up. By releasing all those mental movements, your mind comes into a state of “stillness” or “mushin”.

Mushin Mugamae – your posture reflects your mind
Mushin mugamae is already often discussed in this blog, but without this concept “Stillness in Motion” and “Motion in Stilness” is not possible.

How to gain the skill of Mushin?

I only can speak for myself, ritsuzen is a very effective exercise to create the idea of “stillness” in your mind. During ritsuzen I notice a lot of movements in the body as long I am an observer. The moment that my ego takes over, the feeling of the internal movements will disappear.
Ritsuzen is not a simple exercise and the result comes only after several months of regular exercise.

If you enter the “mushin mugamae” state, your response time becomes much shorter and this is of course beneficial to create “kuzushi.

Kuzushi, the time factor

Kenji Tomiki wrote….

When the equilibrium of the body is lost, the time when the center of gravity is lost is shorter than the time required for the peripheral sensory organ to communicate the loss of the body equilibrium to the nerve center and the latter to order the foot muscles through the foot nerve to put the foot forward; for instance, when the body inclines forward and falls forward because a sudden force is applied from the back, giving the person no time to put the foot forward.

Kuzushi is closely linked with the concept of “Sen” or the timing to move when the opponent decides to make an offensive move. Sen is an extremely complex concept and skill and is built on “Hyoshi”.
Musashi Miyamota wrote about the concept of “hyoshi”. This concept is also discussed many times, but I highly recommend to read “Ma, movement without moving“.

Kenji Tomiki’s time lapse

Benjamin Libet states in his book, “Mind Time: The Temporal Factor in Consciousness (Perspectives in Cognitive Neuroscience),” that it takes 0.5 seconds for the mind to recognise what has occurred.

To create this time lapse, you have fundamentally some options:

  • You wait for the opponent’s attack, use a go-no-sen action and your opponent will be turned back on himself and his attack will suddenly stop.
  • You attack the opponent with a sen-no-sen action, opponent’s reaction depends on his status of allertness. If opponent lost his allertnes you can proceed.

If you create a situation where you can enter into the unconscious mind, your opponent will be turned back on himself and gives you the possibility to control the furhter actions of opponent. Once your pre-0.5 seconds unconscious mind is controlled, you cannot break free from that condition. Usually, after 0.5 seconds, both you and your opponent are in the conscious world, and because such pre-conscious control will not work, it will become a simple exchange of power and technique.

Kuzushi – using mind and body

Using the mind is easy, because we have learned how to use the mind. Unfortunately, our ego is in most cases the driving force behind our movements. When the mind acts as an observer, our subconscious with our stored motion capabilities will take over as a leader.

As Kenji Tomiki has already said, there is a certain lapse of time in the mind and the body of the opponent when you control the body of the opponent through a kuzushi skill. This period of time is very small and you should apply waza coming from the subconscious mind. Don’t let the ego interfere with your actions, you’re always going to be late.

If you focus too much on the 8 methods, you are not allowing the subconscious mind take the right action. If the conscious mind act as an encyclopedia, most of your actions will be readed by the opponent.

Beyond fundamental movements

The wrist grip by the training partner is a “starter” to study the possibilities of kuzushi. Most of these basic forms follow a pre-defined scheme.

As said before, follow the rules, but don’t let the rules controlling you.

When your training partner hold the arms in the chudan position, it is easy to grasp according the “kata method”

When your training partner hold the arm higher, you have to adapt the method of grasping. This is different from the kata method.

Follow the rules, but don’t let the rules controlling you

This simple example can be considered an understanding of the rules and how they should be used.

Basically, kuzushi is a skill at controlling the power of an adversary using certain rules. These rules are explained in a situation that is easily understood in a lot of kata. It is the practitioner’s responsibility to know how these rules or katas can be used in a combat or randori environment.

Some training advice

“One of the most important aspects in the practice of any Budo art is the repetition of techniques or combinations. But, these should not be done just anyhow. Thus, when someone often repeats a certain technique or movement, for example, 500, 1000, or 10,000 repetitions of Tsuki (direct blow of the fist), he must look inward and perceive his sensations, because there is no surely had only two or three of the Tsuki which were correct (speed, power, location), in other words effective. And only those two or three repetitions are important, those are the only ones that we have to remember. To do this, you have to be very receptive and feel the moment when the movement has been done well, look within and register this feeling with the mind and body. Then you have to ask yourself: why at this time did I do it better than the other times? It is the leap from quantitative (quantity) to qualitative (quality). This is what is really important in the learning process: how to move from one level to another. The next time you practice this technique or another, you must try to remember these sensations so that these techniques can be performed successively with this sensation. In this way, in perhaps only one hundred repetitions, you will manage to achieve two or three. Thus, you move faster and faster and you can extend the correct and good feelings to a greater number of techniques. This is one of the keys to moving forward. It is not enough to carry out for 30, 40, or 50 years always the same movement, thousands of repetitions without perceiving or without realizing what is happening in our body, without improving the quality of our techniques, and without trusting exclusively in the repetitions. That’s not enough, you have to find out what was the correct technique, what you feel, and work with that feeling.”

– Taiji Kase – Shotokan Karate

The art of “Kuzushi” in Kyogi-Aikido

Author: Eddy Wolput °1948 – 7th dan Aikido (JAA-Tokyo/Japan) – 5th dan Iaido – 5th dan Jodo.
Part of the material in this article is not directly linked to the Japan Aikido Association (NPO) program or Shodokan approach. Other concepts are incorporated into the study of the subject presented.

Kyogi-Aikido

Kyogi-Aikido is a limited version of the art of Aikido created by Morihei Ueshiba. The goal of Kyogi-Aikido is to introduce some free-play or randori with a limitation in the use of harmful techniques.

In order not to forget the original teachings, some kata or formal demonstrations are created for the presentation to public demonstrations and for grading purposes. This is referred to as “Embu” or a formal demonstration of Aikido techniques that are not permitted during randori. In addition to the Koryu no kata or the original techniques, Embu also includes the formal demonstration of the techniques allowed during randori or freeplay.

Randori kyogi:A competition that enables you to practice Aikido techniques more practically. In tanto randori, one uses a dagger and the other apply techniques freely. The one who have the dagger is changed in the latter part of the game. In toshu randori, players don’t use a dagger and apply techniques each other.
Embu kyogi:Competition of pre-arranged forms. Players show techniques and compete its performance level.

Basic Techniques of Sport Aikido (Tomiki Aikido)
Instructor: INOUE Yoshiomi (7th Dan in Aikido)
Author: KOMATSU Toshiya (5th Dan in Aikido)
Available at Amazon as a paper version or a kindle e-book

Martial art or martial sport?

Most people think that judo, karate and other combat sports are just a game because they are included in the Olympic competition. The implication is that a sport is just for the “game” and cannot be effective for self-defense or fighting. The belief is that the distinction between Sport and Martial Art is that martial artists train for the real world. By real world the assumption is that in addition to street self-defense, other hostile situations are included, such as intimidation and so on.
In the real world, before a new product is used by the general public, it must be tested in different circumstances before it can be used. Fundamentally, a product must be safe and must bring some kind of progress to our lives. A product is not necessarily a physical thing, but it can also be a mental notion.

If a martial art is founded on an almost religious belief and which is not tested in the context of realistic and scientific procedures, this martial art is an illusion and a danger for someone who is a so-called true believer. On the other hand, we must open our minds to ideas and concepts that we regard as controversial. Do not become a true believer who rejects anything that does not belong in the dogma of a so-called true budoka.

Aikido Sport or Kyogi Aikido by removing some of the potential dangers may reach a prominent place as a sports activity, but also as a kind of self-protection. Training in Kyogi Aikido differs in many aspects from the more traditional way of training in Aikido. It produces natural, fast, reflexive movement with the full power safe application, achieving a result against a struggling opponent who is also utilizing the full power while engaging in strategic and tactical resistance using all of his or her resources and training.

Of course, this can go wrong. Winning and losing can become too large and begin to divert the training process. The final goal should not be medal victory. The use of sports competition as a metaphor for a true fight can be very different from a game. Matches, as well as free practice and sparring, are simply different methods to shape the mind and body to deal with the adversity of combat situations.

Just as non-competitive martial arts training may not provide the benefits of competition, training for a sports competition may not provide the full scope of self defense training. Martial sports often include non-competitive components. For example, competition is only a part of the Tomiki Aikido curriculum, and Kenji Tomiki, was very concerned about preserving those self defense techniques that could not be used with full force in free play or randori.

Though martial arts and sports both have higher objectives, it is still a fact that many people train in martial arts primarily for self-defense. For those who have never used sports training methods, or those who have never explored the traditional training of Bujutsu, it is easy to reduce the efficiency of the other. As martial artists we should continually seek opportunities to challenge ourselves by examining the weaknesses of our training and keeping our minds open to other methods.

Kyogi Aikido Limitations

Safety in the first place is possible if we include certain limitations in the practice of randori or freeplay.

Using “Atemi” on a physical weakness of the body can be very dangerous if applied correctly. If not, you can injure yourself with your hand, fist or other part of the body used as a weapon.

As in other martial arts or fighting sport, the use of highly dynamic push is introduced in order to throw the opponent. The target becomes a dynamical weak point of the body. Destabilisation becomes an art in itself. Kuzushi or the art of unbalance becomes an important training element in the curriculum of Kyogi Aikido.

Though not directly harmful, gi-grabbing is not used during shiai and in extension not during randori dojo training. The idea was that gi-grabbing was a part of judo randori. Tomiki’s original idea was to embed atemi-waza and kansetsu-waza into judo training using as a separate randori (kyogi aikido)

Kuzushi – Breaking balance

From the book witten by Komatsu Toshiya:
Breaking Balance and Techniques
When beginners learn techniques by watching advanced players, they tend to look the moment his opponent is thrown. However, it is important to understand “breaking balance” in order to learn the technique quickly. Jigoro Kano, the founder of judo, said that after he studied breaking balance of his opponents, his skills became much better. The result of his research on judo is that “the body balance of people is always broken by pushing or pulling him.” This means that by breaking balance of an opponent, it is possible to apply techniques even if the opponent is powerful. This principle of Judo is the same in Aikido.

Unbalancing the opponent before applying a throw

We have to take in account different aspect about how to unbalance an opponent. Two important aspect have to be considered:

  • Physical unbalancing – break his stable posture and keep your posture
  • Mental unbalancing – finding the unguarded moment by using mushin mugamae

Physical unbalancing

A human body adopts basically always a stable posture because we are under pressure of gravity. Our posture is not always very effective in the maintenance of a balanced posture. Practicing a stable structure is one of the first stages of martial art training. Shizentai and jigotai are both types of posture to introduce stable structure to beginners. Even more experienced practitioners may benefit from practicing shizentai and jigotai.
Physical unbalancing a stable structure is a skill which uses pulling, pushing or rotational movements. These actions can be considered tools for the use of internal and external power.

Power usage needs a stable structure, otherwise the opponent will use your unstable posture to create kuzushi. Maybe that’s new to a number of you. Most explanations of kuzushi only describe how to unbalance someone without explaining how to keep a strong but flexible structure (jukozo).

Most training packages to study kuzushi are rather unrealistic or abstract in character. These exercises are not directly applicable to randori training. Practitioners must adapt these unbalancing movements for practical use in randori.
Nonetheless, formal kuzushi training sets give you the feeling of how an unbalanced movement influences the opponent. Practitioners will also be aware that a stable posture is required.

Mental unbalancing

Mental unbalancing could be described as upsetting or disturbing the equilibrium of a person’s state of mind.
Finding the unguarded moment by using mushin mugamae is the first step to set to disturb opponent’s state of mind.

“Find the vulnerable moment in the opponent at the moment when he launches his attack. This kind of counterattack that is executed in the void instant when your opponent is just beginning to launch his attack is called “deai”.”

Kenji Tokitsu – 1979 – Le voie du karaté – pour une théorie des arts martiaux japonais

Mushin mugamae
To get into an opponent’s state of mind, you have to free yourself from all the thoughts that may disturb you how to see the opponent. In this situation, you may manipulate your opponent by showing an opening for him to attack. But you are ready to counter, or you can attack the moment he is preparing to attack you.

Both are waiting for the signal “Hajime” of the referee. The person who has the tanto is known to the defender as a right-handed striker. However, the tanto is now in the left hand. This disturbed the defender and he shouted: “He is a lefty!” It was time to attack for tanto. Sadly, there was no “Hajime”. The limitations are not always as convenient.

Koryu no kata – Dai Yon (2)

There are different opinions on the meaning of ura-waza.

  • reverse or counter technique, also called kaeshi-waza.
  • alternative performance of kuzushi with application
  • ……….

7-hon no kuzushi ura-waza

In Koryu no kata Dai Yon, the 2nd section is called Ura-waza. This section is build upon the omote-waza discussed in a previous article.
The start of the 7 waza are the 7-hon no kuzushi without the throw of the omote-waza, followed by an alternative action. Some of these actions are applications for randori (restricted free fight) or goshinho waza (aiki self-defence). The “kuzushi” element is a prime factor for a non-muscular approach.

Non- muscular actions

Movement is based upon muscular actions. When we say “non-muscular action”, we are talking about extending muscular actions, and not flexing muscular actions.
For a technical explanation see Encyclopedia Britannica.

Pulling and pushing are 2 different movements, but from a non-muscular point of view both are using an extensor action. Basically all “kuzushi” movements are based upon the non-muscular concept. The moment when we use a flexor action, opponent will intercept and can do a counter movement.

All non-muscular actions in koryu no kata dai yon are movements away from the centre to the outside.

Jodan aigamae & gyakugamae

 

Chudan aigamae & gyakugamae

 

Gedan aigamae & gyakugamae

 

Ushiro

Koryu no kata – Dai Yon (1)

A main component of Dai Yon is the (un)famous 7-hon no kuzushi. The 1st part of the Dai-Yon is about throwing an opponent after acquiring a perfect “kuzushi”. This possibility in a fighting situation will be very rare….although it can happen if…..

Koryu no kata Dai  Yon

  • Nage no kata – omote waza – 7 waza
  • Nage no kata – ura waza – 7 waza
  • Oyo waza* – applications – 11 waza

*Oyo waza designates applications build upon 7-hon no kuzushi basics. 

Nage no kata – omote waza

The 1st part of the kata is build upon the 7-hon no kuzushi. A throwing action is added after the kuzushi.
The focus is on the action of the hand and arm doing the kuzushi. The efficiency of the throw is depending on the elasticity of Tori’s body. When the body is stretched power is stored and can be released into uke’s body.
The dynamics of the kuzushi (loss of balance) will undergo the influence of gravity.
There is a mechanism we have to take in account when we use stretching and release.
With the muscular relaxation, the movement is immediate, in a single time, this movement is much faster than with the muscular system of contraction. If we try to throw with muscular contraction, opponent will sense your intention and will block your movement.
Using meguri and tenshi-kei is necessary to create efficient kuzushi.

aiki age sage009Jodan aigamae & Jodan gyakugamae

Kuzushi is created by using a rotational movement of the hand, followed by a body movement with the elbow as a transfer joint.
When you try to lift the hand and arm, Uke will feel and block your movement.
Jodan aigamae & gyakugamae are actions on the inside of Uke’s arm.

 

 

 

 

Chudan aigamae & Chudan gyakugamae

Kuzushi is created by using a rotational movement of the hand, followed by a body movement with the elbow as a transfer joint.
The skill is to turn opponent’s arm in hineri fashion without stretching opponent’s arm. Rotating the arm is the message.
Chudan aigamae & gyakugamae are actions on the outside of Uke’s arm.

 

 

 

Gedan aigamae & Gedan gyakugamae

Using downward power. No pulling action.

 

 

 

Ushiro

Keep centerline when rotating.

 

 

Ura-waza see in another article soon

Rendo – linking movement segments

Movement segments or the concept of “3”

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

When we consider mainly the physical actions, we can divide a movement segment action in 3 parts:

  • root: source of force for movements
  • joint segments: transfer of force by using the joints of the body
  • tip: end of the line of force or the point of transfer into the opponent

By dividing the human body in 3 major segments we can focus on a smaller part of the body. Each segment can be divided into another 3-part segment. By using this concept of “3”, we can isolate partial movement and focus better on moving the partial segment. By using the skill of rendo or linking skill, whole body movement is created.

  • Upper appendicular segment
  • Central axial segment
  • Lower appendicular segment

The central segment of the human body has 3 parts

  • Head or top of the body.
  • Upper torso – with kyokotsu as control system. Middle of the body.
  • Lower torso – koshi/tanden/yōbu. Base of the body.

The upper appendicular segment, called the arm

  • Shoulder or source
  • Elbow or transfer
  • Hand/wrist or extremity

The lower appendicular segment, called the leg

  • Inguinal crease (mata) or source
  • Knee or transfer
  • Foot/ankle or tip (end of force line – see later)

 3 segments

The article “guide, movement and power” is related with the concept of  “3”.

Segment of central body

Kyokotsu controls the central body. By manipulating kyokotsu, movement of the the arm segment can be controlled.
Kyokotsu has also an effect on the koshi/tanden/yōbu. Of course this area has to be free of tension. The movement of koshi/tanden/yōbu will have an effect on “mata” or inguinal crease.
There are 3 basic movements of the kyokotsu:

  • Forward and backkyokotsu in-out
  • Up and downup & down kyokotsu
  • Figure 8tenshikei solo exercise

Segment of the arm

The power in this segment is a push/pull action. The hand is the leading factor and is a pulling action in the direction of the target, shoulder is the driving factor and is pushing forward. The elbow is transferring the pushing power in coordination with the pull of the hand.

Kyokotsu is controlling the power from koshi/tanden/yōbu and direct the power into the shoulder. The pointing of a finger has a pulling action on the arm, the elbow functions as a transfer for the power in the arm.

 Segment of the leg

lower segment of 3The lower segment (inguinal crease, knee and foot) uses the power of koshi/tanden/yōbu. The power is directed into the front foot, the knee is flexible and is used as a transfer. When the knee is frozen, the power cannot reach the foot. By using the skill of rolling feet, the body will move forward, the back leg is used as a a Nordic** stick for walking.

Some exercises : Weight shift – practical exercises.

** From Wikipedia – Nordic walking

Technique : The cadences of the arms, legs and body are, rhythmically speaking, similar to those used in normal, vigorous, walking. The range of arm movement regulates the length of the stride. Restricted arm movements will mean a natural restricted pelvic motion and stride length. The longer the pole thrust, the longer the stride and more powerful the swing of the pelvis and upper torso.

The body has more than 3 segments

The 3-part segment is of course a part of the whole body, and it is the skill of rendo to use the body as 1 whole part. Dividing in a 3-part segment is only a tool for focusing on a particular dynamic part of the body. We cannot infinite divide parts of the body, because it must be practical during training.

An example:
The end of the leg segment is the ankle/foot. By looking at the foot we can see a new 3-part segment.

  • Heel or source
  • Ball or transfer
  • Toes or end of line

3-part foot

Linking segments

In Tomiki Aikido there are many solo- and partner drills with the purpose to link segments together.

Solo drill
Tandoku undo (tegatana dosa) is one of the favorite solo-drills for linking segments. In the next videoclip, tandoku undo – tegatana dosa is covered from the “segments” point of view. The first part is covering some isolated segment exercises. The linking is covered in the solo-drill of tandoku undo.

Solo exercises from Eddy Wolput on Vimeo.

Partner drill
Basically all aikido techniques or waza can be used as a drill to create a specific skill. Creating the skill of rendo is very basic, unfortunately one of the most difficult to perform. Disturbing balance exercises is an ideal method to create whole body movement. It is not only arm movement, but all the segments needs to be linked to create balance disturbing.
Find here an example