BIOMECHANICS IN JUDO, SIMPLIFIED
By Mark Lonsdale, Judo Training Development
The traditional terms of kuzushi (balance breaking), tsukuri (fitting) and kake (execution) provide the judoka with some guidance as to the steps of a technique but they fall short of really understanding how and why a technique works. For example, a simple term such as kuzushi, which we use every night with our students, does not accurately describe the actions or motion required to off balance the opponent. Was it a pulling or pushing motion and did it have a lifting or rotational component? Kuzushi only describes the intent or result, not the biomechanics to achieve that result.
To better understand how techniques work, and without getting distracted by highly technical terminology, it is necessary to think in more specific biomechanical terms as opposed to traditional generalizations. Coaches, in particular, should be able to describe the biomechanics associated with their sport or any specific technique. Simply being able to accurately translate the name of a judo technique helps with understanding the biomechanics. For example, sasae-tsurikomi-ashi is propping, lifting, pulling, leg (or ankle) throw. This tells the judoka that there is a propping component associated with a lifting and pulling action by Tori. What it does not describe is how to place the foot for propping, or how or where to grip the sleeve or lapel for optimum power in lifting and pulling, and is the lifting component with the arms or legs. This is where it is up to the instructor or coach to impart his or her knowledge of the technical aspects of the technique.
Moving on – a judo coach should be able to explain to an athlete the difference, for example, between a harai-goshi and a harai-makikomi.
Before reading on, ask yourself if you can articulate the differences?
Assuming that a judo student has already learned harai-goshi (an orange belt requirement at my dojo), they should know that the translation is “sweeping hip” throw. They should also know that this technique has a pulling and lifting component to off-balance Uke, followed by a turning movement with the hips and body, a lifting component with the left leg, and a sweeping component with the right leg (for a right handed judoka). The execution requires the continuation of the pulling and rotational components, while changing from an upward lifting direction to a downward force, all while balancing on the left leg. In practice Tori should remain standing and on balance. The problem here is that while many instructors can demonstrate this technique correctly, they struggle at explaining it to their students.
Harai-makikomi, on the other hand, includes all of the above biomechanics, but with a change in the position of Tori’s right arm and an additional winding or wrapping component that is carried into the mat. The added power in harai-makikomi comes from Tori applying all his or her weight onto the right arm of Uke and carrying the technique to the mat. The makikomi family of techniques also require total commitment to the attack to be effective.
The next step is to explain, and then demonstrate to the athlete, how a harai-goshi, that may have been blocked or stalled, can be turned into a harai-makikomi by adding additional weight and force to the harai-goshi. This is done by moving the right hand from a high collar grip over Uke’s head and wrapping tightly into Uke’s right arm. Tori then throws his or her entire weight into the arm in an outward and downward turning motion, at the same time continuing to drive with the legs. The wrapping and turning motion should be continued all the way into the mat so that Tori lands on Uke’s chest, maintaining complete control of Uke’s right arm. If done correctly, this should result in an almost immediate “osaekomi” command from the referee.
As a precautionary note, instructors and coaches should explain to their students and athletes the risks associated with the makikomi family of techniques, and in particular the potential for injury to Uke’s ribs. For this reason, it may be advisable to not allow young juniors to use makikomi in randori, and when practicing to execute the throws into a crash pad.
Finally, this article has intentionally avoided using the more technical terms often associated with the science of biomechanics, such as vectors, since these would only confuse the issue. But at a minimum, a coach should be able to explain the various components of a technique, to include: which body parts are being used; is there a lifting or pulling component with the arms; is there a lifting or sweeping component with the legs; is there a turning or rotational component to the throw; and what part does driving force and body weight play in the execution of the technique.