Newton's Three Laws of Motion in Judo?

Isaac Newton lived in a time before the invention of Judo, and he probably never heard of its predecessor jujitsu. He did, however, sum up almost everything that explains how judo works in his three laws of motion and force. In high school, you learn how Newton was hit on the head by an apple and realized there must be gravity. You then go on to learn that he was actually a great thinker and scientist who postulated some ideas about how the universe worked.

  1. How the First Law Explains Judo Techniques

    • Newton's first law in simple terms is this: an object at rest will stay at rest until an outside force acts on it; an object in uniform motion will stay in uniform motion until an outside force reacts on it. If you add Newton's first law and gravity, you can see that if you get your judo opponent to move in a direction and then place a foot to trip him, this law states he has to overcome inertia to stop in time, which is very hard, or he will trip and fall off balance.

    Second Law of Mass and Acceleration

    • This law states that the relationship of an object's mass and acceleration are inversely proportional, and that force is the sum of those two. This means that a larger opponent is harder to stop when he is in motion, because he has more intrinsic force. Using this, the judo player may take advantage of his opponent's motion and pull him in the same direction he was originally going to accelerate him into a throw or trip using his own momentum.

    Third Law Applications

    • The third law is a simple one with big ramifications. It states that for every action there is an equal and opposite reaction. In the strategy of judo, there are many times this is used. If, for example, you want to throw your opponent to the left, you might start by pushing or puling him to the right. His natural reaction should be to resist and push back. As he does this, you change your direction of force so that you are both pushing in the same direction and he has just helped you throw him.

    Gravity of the Situation

    • These laws allow for explanation of almost all of the strategies and tactics in judo. You are taught as a player of judo to pull or push your opponent off balance while keeping your own balance. This means you have to push or pull his center of gravity past his ability to support it.

    Real Practice of the Third Law

    • Judo is a game of action and reaction, so don't take too much time on the mat to ponder Newton. Your reactions have to be equal in force and also in timing to win, so save your discussion of principles until after the match.