2. How Can Dynamics Be Applied

If we wish to carry a heavy load somewhere, we use certain required tools or machines to economize our energy and time. For instance, if we are putting a large stone on a truck, by leaning a plane surface against the truck and making the stone roll or slide along it we can easily do the work, economizing our energy and, in the end, our time. This is taking advantage of both the law of resolution of forces and the law of friction, and if, in addition, we use a lever, we can do the work even more easily. This is taking advantage of the law of moment. We can make the stone roll or turn over to the right or left at will by taking advantage of dynamics. But how about the human body? A human body has a nervous system, so it can perceive your intention and make motions at its own will.

In competitive sports such as judo, wrestling, and boxing, the opponent does not move as you want. On the contrary, he will move in a direction inconvenient to your attack and defense. Hence it is difficult for you to throw or put him down, though you want to do so. Let us take an example. Seeing your opponent advance in a larger step than usual and about to rest his weight on the forward foot, you try to make him fall by sweeping his foot with your foot. But you will never succeed in felling him because his weight has already been put on the foot. Again, if you try to throw him by holding his waist with your arms, he will suddenly lower his waist. So you will not succeed in your objective because his resisting force becomes heavier than yours. Thus, in judo, the opponent tries to put his body in a position inconvenient to your attack and defense. Seemingly it is im­possible for you to throw or put him down by taking advantage of dynamics. In fact, however, a small man can throw a larger man down like a puppy and hold him down easily. When you are thrown or held down, you will see many laws of dynamics at work, and you will know that they prevail.

What causes this? Isn't a human body different from a stone or a load? Doesn't it have a nervous system that makes it move freely? Two reasons can be given in answer. The first is that reaction time must be considered whenever your opponent makes a movement. The second is that you have the ability to make yourself harmonize with him. This enables you to take advantage of an opportunity to attack him; that is, to take advantage of his reaction time.

Nervous system

Now let us consider the nervous system. The nerves run through all parts of the body. The chief nerve centers are the brain, the spinal cord, and the sympathetic ganglia, but only the first two of these are important to the present discussion. The spinal cord runs down the spinal column. From the spinal cord a large number of nerves pass out between the vertebrae. The spinal nerves can be divided into two kinds: the sensory and the motor nerves.

1.         Sensory nerves (five senses: sight, touch, taste, hearing, smell)

Why are you able to perceive your opponent's touch on your body or a change in his posture? It is because the sensory nerves running through your body are excited by external stimuli, and the resulting excitement is carried up to the sensory nerve center in the vertebrae and the joint nerve center in the cerebrum. The joint nerve center has the ability to feel excitement and remember it. By will, it can send out messages to the motor nerve center in the motor area of the cerebral cortex.

2.         Motor nerves   (control of muscular action:   movement of fingers, working, talking, etc.)

We can make our bodies move because the muscles contract to pull the bones to which they are attached at the joints. The messages produced in the sensory area of the cerebral cortex are carried first to the motor nerve center in the motor area of the cerebral cortex, then to the vertebrae, and finally to the motor nerves running minutely through the muscles. The motor nerves there cause the proper muscles to contract. So, if the message is stopped somewhere before it reaches the end of the line, the muscles cannot contract. For instance, if the motor nerve center above the hip is broken, the leg cannot be moved at all. Again, if the motor nerves that pass through the wrist are cut off on the way, the fingers cannot move. As in the case of motor nerves, if the sensory nerve is broken, the same thing happens in the sensory area of the cerebral cortex; that is, you are shut off from everything external to the broken nerve. Now, there is an important matter with regard to the sending of stimuli and messages. This is reaction time. Let us next study this.

Reaction time

In excitation and message transfer, a time gap, like a physical solid, occurs between the stimulus and the contraction of the muscles. This time gap is called reaction time.

1.    Reaction quickened by exercise

It is not known how stimuli are accepted by the joint nerve center, changed into messages, and carried to the motor nerve center, but it is clear that the time needed to produce the messages and carry them to the motor area of the cerebral cortex takes up most of the reaction time. If the same stimulus is repeatedly given, the time required for reaction is made extremely short.

Suppose a man who has never ridden a bicycle tries to ride one. At first he will probably not be able to operate it because his motor nerves do not know how to make his body balance or move when the bicycle starts to fall to the ground. Perhaps the motor nerve center has neither yet received any message from the sensory area of the cerebral cortex nor accepted the right message from it. The same thing can be said for all sports, but if the same stimulus is repeated, the joint nerve center will act correctly and, eventually, independently of one's will. Consequently, the reaction time becomes extremely short —almost like that of an unconditioned reflex (see below). Thus one learns by constant practice to ride a bicycle.

3. Unconditioned reflex. Finger contracts automatically when pricked by sharp point of pen.

2.    Unconditioned reflex action

If you prick your hand with a needle, you instantly pull back your hand reflexively. A bucket of water suddenly poured on your head will make you jump up reflexively. When something suddenly gets into your eye, you blink reflexively. These reactions are called unconditioned reflex actions. In these cases the stimulus is not carried to the brain but stops on the way at a vertebra where a message is produced to be sent reflexively to the motor nerve. So the path of both message and stimulus is shorter than the one that goes through the brain.

4. Conditioned reflex. Cat has been con­ditioned to behavior pattern of drink­ing milk daily at 12 noon upon ring­ing of bell.

3.    Conditioned  reflex action

The  conditioned  reflex  was  discovered  by Dr.  Pavlov,  a famous Russian scientist, in an experiment with a dog. A dog salivates when he eats. If a bell is rung whenever he is given food, and if this action is repeated over a period of time, the dog eventually salivates at the sound of the bell, even though he is given no food.

There is a direct relation between the flow of saliva and the food but no relation between the flow of saliva and the sound of the bell. Thus when the sound of the bell, which has no relation to the flow of saliva, is put in relation, naturally or artificially, with the reaction of producing saliva, this reaction is called conditioned reflex action. Let us give two examples.

Schoolboys get hungry the instant they hear the school bell ring for lunch. You will pull back your right arm the instant the opponent who is trying to apply right hane-goshi (a technique to be explained later) pivots to the left, since you have become accustomed to this way of defending yourself from hane-goshi as a result of long practice. In these cases the joint nerve center is never troubled. Thus no time is allowed for the joint nerve center to judge stimuli and send messages.

It is clear that the unconditioned reflex action is the shortest of the three reactions, since the path is the shortest. Next comes the conditioned reflex action, in which no time is spent in judging the stimulus and sending a message. The slowest is the reaction that travels through the joint nerve center, but we have learned that it can be shortened almost to the time span of the first by hard practice repeated daily.

4.    Evaluation of the use of these three reactions in judo

a.    Unconditioned reflex action

Since this reflex action is unrelated to the joint nerve center, it tends to result unconditionally from any given stimulus. In judo or boxing, for instance, if your opponent makes a movement toward your face, you are apt to close your eyes. You must not do this. If you close your eyes you cannot see him for the moment. This momentary blindness of yours gives him a good chance to attack you. Therefore this reaction must be checked by continual training.

b.         Conditioned reflex action

Since this type of reaction rarely troubles the joint nerve center and comes after long acclimatization to the same stimulus, it is similar to the unconditioned reaction. In judo this reflex may not always be useful because other stimuli may be confused in certain techniques. Your opponent may take advantage of this reflex by a feint. So your joint nerve center should, first of all, analyze the various given conditions correctly and send suitable messages to the various areas.

c.         Reaction achieved by practice

If you react after judgment is made in the joint nerve center, you take all the given stimuli into consideration. Therefore, unlike the conditioned reflex, which is open to deception, reaction achieved by practice enables you to exercise correct judgment in each case. It is necessary in the study of all techniques. It is not useful in a contest unless the reaction time is shortened almost to that of an unconditioned reflex action. This can be attained by continual training over a long period of time.

In judo the third type of reaction (reaction by practice) is the best of the three, and the second type (conditioned reflex action) comes next. The first type (unconditioned reflex action) does not have much use in judo.
We have studied the three kinds of short reaction time. Let us now study some cases in which the reaction time is longer.

Nine cases in which reaction time becomes longer

The following are typical situations or conditions in which the time required for reaction becomes longer:

1. When one is not trained in judo.
2. When one's mind or body is fatigued.
3. When one is absent-minded.
4. When one is emotionally upset.

These cases, except the first, usually occur in daily life. Even if your opponent is not proficient in judo, he will expose these weak­nesses in you.

5. Object and image. Reaction time varies with clarity ofimage upon retina.

Next let us consider how you can lengthen the reaction time of your opponent.

5. When your opponent focuses his attention on one movement, his reaction time to another stimulus becomes long. For instance, if you try to apply hane-goshi in the left direction, your opponent will try to defend himself in that direction. At this moment his attention will probably be fixed in that direction only. Therefore his reaction time in the opposite direction becomes longer.
6. When stimuli are combined, the reaction time becomes longer. If your opponent knows that you can apply hane-goshi from both sides, he must be ready for an attack from both sides. Therefore his reaction time becomes longer.When we see a movement by indirect sight, the reaction time to that movement becomes longer.
7. When you see an object, you see some parts more clearly than the others because the central fovia of the retina can image an object clearly, but the other parts cannot.

(See Figure 5.) Therefore, if you attack your opponent from a direc­tion in which your movement cannot be clearly imaged, his reaction time becomes long.

8. When your opponent inhales, his reaction time is longer than when he exhales. We can exert a stronger force when we exhale than when we inhale. While inhaling, your opponent will find it difficult to defend himself against your attack, whether he be a master or a beginner in judo.
9. The moment your opponent is off balance in any direction, his reaction time becomes longer.

The unguarded moment

In addition to the foregoing nine examples of long reaction time, we must note that it takes time to move a physical solid. For example, the body or the waist and abdominal region cannot be moved as fast as the fingers or the arms. Therefore, if you are in an incorrect posture (especially standing in an unstable posture), it will take a relatively long time before you can react and take a defensive posture against your opponent's attack. It sometimes takes one-fourth to one-half a second to move into a defensive position.

What will happen if you break your opponent's posture when his long reaction time begins ? He must face you unguarded. If you want to throw him, put him in such a position both physically and mentally that it takes him a longer time to get into a defensive posture; that is, break his posture. At the same time put yourself in a position, physically and mentally, in which you can attack him in as short a time as that of a reflex action. Then apply your technique. You can easily throw him. In this case you can dispose of him at will by the maximum use of dynamics.

Now let us study the cause that induces such an unguarded condi­tion in your opponent. This factor has already been studied in the first chapter; it is that of harmonizing yourself with your opponent. To master it, you must learn the techniques of judo dynamically and physiologically and train your body to move effortlessly. In a contest, keep your mind always calm and peaceful—never get excited or panicky—so that you may systematize all the thoughts or stimuli that come into your mind into a cosmos, as an artist does when he is painting a work of art. There will be no curtain to separate you from your opponent. You will become one with him. You and your opponent will no longer be two bodies separated physically from each other but a single entity, physically, mentally, and spiritually inseparable. Therefore the motion of your opponent may be considered your motion. And you can lure him to any posture you like and effectively apply a large force on him. You can throw him as easily as you can yourself.

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