Judo is based on sound biomechanical principles. The more efficiently a person applies these principles, the more effectively that person will do judo. To do judo well, a person must know not only how to control his own body but also his opponent's.
Learn Japanese Phrases
The Japanese phrases, terms, and names—in use since judo's inception and familiar to all judo practitioners—explain much of what judo is and does. You just have to appreciate them and use them to explore the fullness and complexity of the art. For the most part, terms such as kuzushi, tsurikomi, and many others—terms we often use without giving them much thought—are based on sound biomechanical principles. Words do indeed have meaning and purpose and, for the most part, the Japanese names in judo translate into functional application.
Typical examples are kuzushi, tsukuri, and kake. These well-known terms describe both a physical action and the theoretical concept behind that physical action. Kuzushi translates to "breaking down" and describes the action of breaking down an opponent's balance and posture. Tsukuri translates to "building or erecting" something and describes the attacker's action of building or forming his technique. Kake translates to "suspend, hoist, or raise" and describes how the attacker raises or suspends his opponent up off the mat in the actual execution of the attack. The meanings of the terms neatly describe the action involved.
Controlling how an opponent moves is vital to success in judo, as well as in any other combat sport. Judo is movement. A judo practitioner must be able to control how his own body moves but has the added burden of controlling how his opponent moves as well. Making your opponent move the way you want him to and controlling as much of what goes on in a judo match determine who wins and who loses. Make no mistake about it: judo is one of the toughest sports ever invented. Judo is also an effective method of developing fitness and health, useful for self- defense, and ideal for developing a sound character. But when it comes down to it, if you want to be good at judo, you have to know how to move an opponent and move him with a high ratio of success.
Controlling the movement of a partner in practice is different than controlling the body movement of an uncooperative and resisting opponent in a judo match. For a technical skill to be effective in a competitive situation, there has to be a reliable foundation for it. This foundation is the physical education aspect of judo. The biomechanical principles that are the foundation of how and why judo works in a sporting context are the same principles that govern judo as a method of study in physical education.
Throughout my coaching career, I've used the phrase "control judo" to describe how to effectively teach the functional movements necessary for success in judo. The basic idea is for the athlete (and the coach who prepares that athlete) to control as much of the action in a match as possible. In any conflict with another human being, you must control every aspect of that conflict, and you must leave nothing to chance. Whether in competition or self-defense, controlling an opponent is the ultimate goal.
Physical Education
Judo may appear to be a competitive sport, the fact remains that judo is first and foremost a method of physical education. A major part of physical education is the teaching of good sportsmanship. Good sportsmanship is basically good ethics applied to a sport. These good ethics taught on the mat are what develop good character and a decent human being. Judo's founder, Prof. Jigoro Kano, placed primary emphasis on judo as physical education and secondary emphasis on judo as a sport.
That said, millions of people all over the world practice judo as a competitive sport. Judo's expansion from Japan to the rest of the world has been mostly due to people pursuing judo as the exciting sport that it is. From a technical point of view, judo's development has come largely from the coaches and athletes who compete in it. All of these people have pushed the envelope in search of improved technical skills to get the edge on opponents. Judo tests and pushes the boundaries of human movement. What allow those boundaries to be pushed are the sound biomechanical principles rooted in the physical education aspect of judo. Without its foundation in physical education, judo as a sport would not be the technically compelling activity it is today.
Judo was my first exposure to the world of martial arts. I was twelve. But along the way I developed keen interests in both jujitsu and sambo and am a firm believer in the concept of cross-training. Judo and similar combat sports are complex activities based on sound biomechanical principles and each art provides its own perspective that is worth exploring. But historically, judo is the root discipline of most of today's combat grappling sports, and because of this, I will use judo as the primary sport when I explain the biomechanics of a technical skill or movement.
The principles of judo initially developed by Prof. Jigoro Kano have stood the test of time because everything he did was based on sound biomechanical principles. As mentioned, much of the Japanese terminology in judo most students tend to take for granted is based on fundamentally sound concepts. These concepts are considered "old school" but have stood the test of time, because they continue to explain why and how the human body works most efficiently in the context of judo. Along the same lines, one of the most brilliant things Jigoro Kano did was to give a descriptive name to each of the different actions in judo. An example is shintai. Shintai is the term used to describe movement, most usually in a linear pattern. From that, we have the different footwork or movement patterns of ayumi ashi, or normal walking; tsugi ashi, or shuffling footwork; and taisabaki, or body movement in a circular pattern. Each of these movement patterns are part of the overall concept of shintai.
From my research, prior to Jigoro Kano and Kodokan Judo, no hand-to-hand fighting art (such as the different feudal Japanese jujutsu schools) had specific names for specific movements based on their function. Prof. Kano largely brought this method of describing things to the names he gave to the different throws, pins, strangles, and armlocks in Kodokan Judo.
For the most part, the name of a technique provides a description as to how that technique should optimally work. This pragmatic, simple, and logical concept of naming things has ensured that the biomechanical principles of Kano's judo have stood the test of time with continued success.
The Japanese language is considered to be the common language used to describe the techniques, theory, and concepts of judo much in the same way Latin is used in science and law. This has helped tremendously in the promulgation, teaching, and explaining of judo. If the Japanese terminology were no longer used, much of the analytical understanding and appreciation of judo would be lost.
It is a good idea for any serious student of judo (or similar martial art) to learn and understand the Japanese names and phrases to better appreciate the underlying concept of a particular movement or technique. A person doesn't have to speak or read Japanese fluently, but it does take an accurate understanding of the terms to better understand what a particular name or phrase really means. As noted, in most cases Prof. Kano named things based on their function.
Kinesiology in Action
Judo is kinesiology in action. Kinesiology is the study of the human body's movement, and that describes judo very well. Knowing how to control an opponent's body and then actually doing it defines success in judo. Movement and the control of movement are what keep judo practitioners up at night, and I am no different. I certainly am not an academic, but I do possess a fair amount of education, practical training, and experience in how to make a human body work and how to do so optimally under the stress of training and competition. It is safe to say that all books stand on the work of those who have come before them.
The above is an excerpt from the Judo Advantage: Controlling Movement with Modern Kinesiology by Steve Scott, publication date March 2019, YMAA Publication Center, ISBN: 9781594396281