The Mutual Relationship of Throwing and Movement Directions in Judo

by Elie A. Morrell, Shichidan

When one scrutinizes the repertoire of judo throws, it becomes apparent that most throws will fall into a particular ‘Direction of Throwing’ category. To be specific, the direction of throw is that which exists at the moment of kake and relates to the opponent and not the attacker.

Throws such as Harai Goshi, Koshi Guruma, Tsurikomi Goshi, and O Goshi are techniques with a throwing direction generally to the opponent’s right or left fcont comers, depending on the attacker’s gripping preference.

Throws such as O Soto Gari, O Uchi Gari, and Ko Soto Gari result in a throwing direction generally to the opponent’s right or left rear comers.

Before discussing the issue of the mutual relationship of throwing and movement directions, some comments are warranted regarding what is known as attacking and throwing spaces.

When referring to space as it relates to the two players, it is basically the space existing between the two players at any given moment. The two common spatial terms are known as the attacking and throwing spaces.

An attacker prior to launching into a throwing technique normally requires maximum attacking space between the two players. This then allows the attacker to generate the necessary momentum to pull off the technique.

At the instant kake is reached, the space between the two players is minimal or zero, depending on the type of technique attempted. This space is the throwing space.

For the two players standing in a natural posture, the natural attacking space would be full extension of the arms. This space is affected to some degree if the player(s) adopted a crouching (jigotai) posture and/or some shoulder rotation was evident.

A common belief among some judo practitioners is the philosophy that it is best to attempt to throw the opponent to his/her front (right, left or direct) while the defender is moving backward.

The author believes that this thinking is based on the premise that the attacking space is maximized when the opponent moves away from the attacker. This of course is not true. As indicated earlier, attacking space is controlled solely by the hands/arms. Therefore, direction of movement does not govern the attacking space.

To illustrate the mutual relationship that exists between the throwing and movement directions we will examine O Soto Gari and Seoi Nage. These are examples of forward and rearward throwing direction techniques. O Soto Gari will be examined first.

When the attacker and defender hereafter called ‘A’ and ‘B’ respectively, are moving, and no pulling or pushing exists, the two players for all practical purposes move as an entity. The total momentum thus generated can be said to be speed of movement multiplied by the sum of the two body masses. Let us now consider that ‘A’ attacks ‘B’ while ‘B’ is moving backward. In this case the throwing direction matches the direction of movement and the direction of the generated momentum. What ‘A’ now has to do is close the attacking space followed by a tightening up of the throwing space. To accomplish this, ‘A’ needs to slightly increase his own momentum while ‘B’ is still moving backward. Thus the overall momentum is increased without any disturbance to that which already existed for ‘B’. At the instant the power point (Kake) is reached in the attack, (where ‘B’s leg is reaped away) maximum force will be achieved. The power point was thus reached without a change in movement direction or momentum of player ‘B’.

The same attack (O Soto Gari), made while ‘B’ moves forward is a different situation. The throwing direction is unchanged. ‘B’ is to be thrown to the rear. It will be readily noticed that ‘B’s direction of momentum must now be changed. In order to throw ‘B’ to the rear, ‘A’ has to offset the forward momentum of ‘B’. ‘A’ must still close the attacking space as in the previous example. But he also has to in effect reduce the forward momentum of ‘B’ to zero, then build it up again in the opposite direction! Therefore ‘A’ is required to do far more work to achieve the same result. We can conclude from this that it is far more effective in terms of energy output to make a rear throw while the defender is moving to the rear.

When Seoi Nage is examined, the rationale for determining the energy output of ‘A’ is similar. A basic difference for Seoi Nage requires that ‘A’ turn his body to perhaps a full half turn. This is a physiological requirement imposed on ‘A’ to effect the technique. The throwing requirements remain essentially the same (i.e. driving leg, attacking leg, if required, locking hand, etc…). Again, if ‘A’ were to attempt to throw ‘B’ forward while ‘B’ was moving backward, the same problem arises as that encountered while attempting O Soto Gari while ‘B’ is moving forward. That is, the direction of momentum must be changed in order to throw ‘B’ forward.

From the foregoing, we can conclude that minimum energy requirements are met when ‘A’ throws ‘B’ to the rear when ‘B’ moves backwards or throws ‘B’ forward as ‘B’ moves forward.

The foregoing observations are based on scientific principles. It must be remembered that no two individuals are alike and that judo skill is made to fit the individual and not vice versa. If students feel better and find it easier to do techniques which appear to violate scientific principles they should not be coerced into changing their method of approach.

Finally, consider the Nage No Kata. Every technique in this form complies with minimum energy requirements. That is, throwing direction matches the Uke’s direction of movement.

One throw in the Nage No Kata would apparently appear to contradict the foregoing discussion for justifying the existence of the mutual relationship of throwing and movement directions.

That throw is Yoko Guruma. This is one of the four blow throws with Uke moving forward to attack tori. The defensive/offensive moves of tori involve his first attempting Ura Nage followed by Yoko Guruma. Uke’s reaction to the Ura Nage attempt by tori momentarily reduces his momentum to zero. However, he generates an opposing force to the Ura Nage which allows the tori to attack with Yoko Guruma. Uke’s resultant Ukemi impact zone is basically directly to either his direct right or left of his initial direction of movement.

In formulating the Nage No Kata, Dr. Kano has presented a classic example of his judo maxim of “Maximum Efficiency with Minimum Effort”. No throws are made in a direction opposite to the Uke’s direction of movement!