Technical Aikido


By Mitsunari Kanai, 8th Dan, Shihan

Chief Instructor of New England Aikikai (1966-2004)

Chapter 4 – Relationship between Joints and Power, and How Power is Produced

Part 1
We will now examine the relationship between the body’s joints and power, and how correctuse of the body’s joints produces power.In examining this subject, we can begin to understand the expression of AIKIDO on thephysical level, and by focusing on the nature of the body, understand the concept of unificationof mind, body and spiritThe concept of unification has suffered because it has usually been a very vague concept. Inthe past, emphasis on the mind aspect of unification (mainly “how-to-use-KI” ideas) has beenused to compensate for the fundamental contradictions and appearance of disunity of AIKIDO’swidely varied collection of attacks, joint techniques and throwing techniquesHowever, as I hope is becoming clear through the previous discussion, it is my belief that byanalyzing the workings of the body, a clear and effective logic can be defined and establishedfor AIKIDO practice.

If we use the logic of the physical body as a basis for clarifying what would otherwise be thevague concept of “unification”, we can begin to clarify one’s understanding, and escape theambiguities in most In order to gain this much deeper understanding of AIKIDO, you must learnto use your “entire-self” in AIKIDO practice.Expressed in physical terms, using your entire-self means that you must use your entire body inperforming each movement or technique. Moreover, since the joints are the structures thatconnect the various parts of the body you must use all of the joints of your body. To do this youmust understand the function of the joints of the human body.There are three important functions of the joints:

First, appropriate and flexible joint movement can soften or avoid a collision with an opponent’spower.Second, joints can create flexibility. Each individual joint has a range of motion, but in order tomaximize total body flexibility, one must make all of the joints, including the hip joints, adjustfrom moment to moment..The more joints that can be adjusted in a coordinated way, the more the body will be totallyflexible.Third, joints can produce power. Muscles create power, and multiple muscles and theirassociated connective tendons are attached to each joint. When multiple muscles are used inan organized way, the power created necessarily must be proportional to the number ofmuscles used. This power is manifested through a movement of the joint to which the musclesare connected. If this is true of one joint, then it is better to use two joints than one, and threejoints than two, etc. The more joints one uses, the greater the power one can generate andtransfer to the opponent

Part 2
When multiple muscles are used in an organized way, the power created necessarily must beproportional to the number of muscles used.

Let us further examine this concept by taking a conventional CHU-DAN-I-TSUKI (Mid levelthrust) attack as an example.When you try to thrust an object with proper MA-AI (distance), you open both legs slightly widerthan SHIZEN-TAI (natural standing posture) and lower your hips. From this stabilized posture,you place your right fist to the waist, extend your left hand straight forward, and then quicklypull your left hand to the left waist.By using the reactionary power from this rapid pulling motion of the left fist, you strike yourright fist forward from your right side at waist level. Just before the right elbow fully stretchesout, you twist the fist inward. You hit the object at the moment when you simultaneouslytighten your fist and body muscles. At this moment, you keep power in your body by holdingyour breath.In analyzing this thrust, it becomes clear that, in addition to the reactionary power from left fistpulling and the twisting power of right fist, the only joint that is effectively used to convert bodymovement to power is the right elbow joint (and, to a lesser extent, a slight hip twist).

This basic CHU-DAN-I-TSUKI can be explained further as follows: the tension power of multiplemuscles surrounding the elbow joint is converted to the speed of the striking motion and thisspeed, in turn, is converted tostriking power. This striking power (or colliding power) is transmitted to the target object whenyou support the striking power with your own stable body.However, this basic CHU-DAN-I-TSUKI is not a perfect posture from the point of view ofphysical dynamics. In fact, if this imperfect posture can be maintained when you strike anobject, it means that the reaction from the power which is transmitted to the object is small, andtherefore the amount of power transmitted is likewise small.As long as one maintains this conventional approach to the use of the body to generate power,one can never grasp a logic of AIKIDO. In other words, this approach is a limited, and, moreimportantly, a non-AIKIDO way, of using the body and generating power. It is a non-AIKIDO waybecause the final movement is not connected to KI or the release of power.Moreover, less joints and muscles are used because of the limited use of the KOSHI.

Also,holding the breath while moving means power will be held in the body by tight muscles.Conversely, the release of the breath allows the muscles to relax and, by increasing flexibilitythrough relaxation, permits more muscles to participate in the movement. Therefore, release ofthe breath means relaxation of the muscles, release of power, and release of KI.I will explain this further.

This CHU-DAN-I-TSUKI is done by using one elbow joint, and byutilizing a small hip twist and the body weight. However, the hip twisting and the body weightshifting are not effectively applied because the amount of body weight shifting is so small thatit does not require the back foot to be aligned and employed in the creation of the movement.It isthe use of the back foot to create power and stabilize the body weight, enlarge the size of thehip and leg movement, and augment the movement through the use of weight shifting thatallows one to create a release of power.To do this technique so as to embody the logic of AIKIDO, one would proceed as follows: Ifone starts from HIDARI HANMI (left HANMI), the movement should start by twisting the hip tothe right. Subsequently, when twisting back the hip, this hip rotational power should betransferred to the shoulder joint rotational power, then to the elbow joint rotational power aswell as the arm stretching power. Finally, simultaneously using the speed of this movement togenerate power, while applying a snap to the wrist, and putting all the body weight on the leftfoot, one uses this left foot (which becomes the back foot) as a spring board, to push off from.Thus body weight shifting, rotation of multiple joints, and speed are converted to generateimpact power as one strikes the object.

The technique of breathing also illustrates two approaches to this technique. Holding thebreath tends to keep the muscles tight (rather than relaxed). But, if the breath is released at themoment of the strike several things are achieved, among them, that the muscles are therebyrelaxed and therefore capable of generating greater power. Release of the breath correlateswith the release of power, as well as release of KI.The back foot (left foot) must be straight enough to be a “strut” at the moment of impact. Forthe right arm, the elbow must be facing down and the palm side of SEI KEN (basic fist) must befacing up and the arm must be extended straight.If the posture is maintained correctly, this CHU-DAN-I-TSUKI can logically yield a much greaterinstantaneous power than the conventional CHU-DAN-I-TSUKI . In addition, it permits you tomaintain sufficient balance despite the reactionary power generated by the impact.

Twisting or reverse-twisting of the hips as an initial starting movement converts the speed ofthe elastic or rotational motion of the entire body’s joints to power, and, accompanied by agood take-off (using the rear leg as a spring board) also converts the force of gravity intopower during the body weight shifting. Finally, it converts in an orderly manner, compression ofbody air to power as KOKYU RYOKU (release of breath). This is the most practical andAIKIDO-like way of producing power.If the above described striking method (I call it FURI TSUKI from JODAN, i.e. “Swinging thrustfrom JODAN”) is further developed or perfected by training, the exact same motion can beapplied to the AIKIDO throwing techniques or joint techniques.

To explain further, it is important to realize that the lower half of the body utilizes two types ofmovement to produce two different kinds of power. One movement is the horizontal planerotational movement called KOSHI twist and reverse-twist, and the other is horizontal planeforward movement created by body weight shifting when the foot moves forward.This power, produced by the lower half of the body, is transmitted to the shoulder where avertical plane rotational movement of the shoulder joints generates centrifugal force which isthen transmitted through the elbow’s stretch and twist, and further converted to the power ofthe wrist snap. Thus different types of power are also produced in the upper half of the body.

Although different types of power are produced in the upper and lower body, it is important tokeep in mind that the lower body, in general, produces power from movements in a horizontalplane, and the upper body produces power from movements in a vertical plane. This theorycan be applied directly to a technique like IRIMI NAGE. It is absolutely necessary that youorganize your thoughts along these lines and apply them to your technique.I stated earlier that, theoretically, power generated from a movement is proportional to thenumber of joints involved. However, in reality, when a number of unique kinds of power,produced in diverse parts of the body, are put together, their combination actually generatesmore than the simple mathematical sum (or total value of power), of each power produced byeach joint and its associated muscles. This can be called a synergistic effect.To utilize one’s own body to produce this synergy is the key point of AIKIDO’s way of using thebody.As I hope this explanation makes clear, I believe an effective logic, which surpasses pastconcepts, can be established for AIKIDO practice.If this logic is used as a basis for analyzing movement, the ambiguity of AIKIDO explanation ofthe past can be solved; it is no longer necessary to rely on so called “mental” aspects ofAIKIDO to explain it.

Only after AIKIDO can be logically explained on the physical/body level isit then possible to extend the explanation to the mental and spiritual levels and proceedtoward a clear explanation of KI.As long as ambiguity exists regarding the proper use of the body it is not possible that ourinvestigation into the many aspects of AIKIDO will result in a real understanding of KI. Withoutclarification of the physical dynamics of AIKIDO, an explanation of KI will be doomed.Only when an AIKIDO technique contains the characteristics of AIKIDO, consistent with theabove-described logic, can we clearly state it is AIKIDO. And because of the existence of thislogic in AIKIDO, AIKIDO’s application to the use of weapons is possible and, beyond weaponstechniques, limitless expansion of technique is possible. This is what makes possible the brighthope of the continuous development of AIKIDO.