Archive for physics

Can you teach what you don’t understand?

Posted in martial arts, teaching with tags , , , on May 2, 2010 by serpentstaff

I was put in mind of this question when I read some comments a colleague had made about board-breaking. Breaking boards is unquestionably an exercise in physics. But my colleague, through his remarks, revealed that he didn’t quite understand the physics involved. Now, he is an excellent martial artist and a fine instructor. Furthermore, if students followed the practical instructions he was stressing at the time, they’d probably be helped in their chances of breaking their boards. The only problem would come if they relied on his underlying explanation when taking a physics test. And if they were taking a physics test, they would most likely have already figured out his mistake… No harm done?

In fact, the physics of board-breaking is an area where many good instructors have gaps in understanding. Everyone throws around “F=ma” and talks about acceleration, usually with the idea of ‘acceleration’ as ‘picking up speed,’ and ‘mass’ as ‘how much you weigh.’ Technically, these ideas don’t offer a complete, accurate account of what’s going on, but if you can get your students’ techniques to pick up a lot of speed and make effective use of their body mass on the way to striking a board in the right place with the right surface — you’ll have helped them succeed.

At the same time, too much technical knowledge can get in the way. Some of the most unhelpful instructors I’ve known, with respect to board-breaking, have been engineers. They’ve known their basic physics, and have insisted on principles that would apply if a rigid steel battering ram were being driven on a horizontal plane into a board. If you’re talking about getting a human body part to crash optimally through a stack of wood, things are more complicated than that. Biomechanics are involved — bones, muscles, joints rotating various ways, varying degrees of flexibility and strength. A human body kicking is not a battering ram on a straight path, and if you try to get it to act like one, you can really cramp its power. The non-engineer, without preconceived ideas, may do better in helping the student generate more force through an excellent technique suited to that student’s body.

Even a biomechanical engineer with all the right knowledge and understanding (if there is such a person) might not have anything over the non-engineer instructor, where teaching martial arts is concerned. That is, they might be able to describe what happened after the fact, but they might not have any advantage in getting the student to perform better. Martial movements exist only in their performance; they are learned through repetition and feel. The martial artist need not understand the underlying physics in order to embody it, and teachers or coaches just might not need any of that understanding to do their jobs. Lacking the understanding, they can still make effective use of terms and concepts, more or less as metaphors to help students imagine what they need to do.

Another idea that’s often used in martial arts instruction, but just as often (I’m willing to bet) not understood, is the concept of ‘ki’ or ‘chi.’ There are those who don’t believe in the first place that it’s something “real,” but even the fervent believers are hard pressed to explain it. Yet (I’d argue) it’s used very effectively by many instructors to help their students improve technique. Through exercises in visualization (like “the unbendable arm”), and exhortations that may be more metaphorical than anything else (“relax; use your chi!” “flow your ki;” “use ki, not muscle!”), instructors manage to get students to reserve energy, move easily, and generate effortless power in their techniques. One could argue that they are getting students to “flow their ki,” whether or not that’s something either party really comprehends.

But what do you think, readers? Can you teach what you don’t understand?