Angular momentum

Apologies for being so quiet lately. I thought that I’d share this little blog post examining sayabiki (the pulling back of the scabbard with the left hand to draw the Japanese katana with the right hand) from the physicist’s perspective of conservation of angular momentum:

Sayabiki and Angular Momentum

This is an interesting point, although I think that it is more relevant to, say, the dynamics of a throw in Aikidō than drawing the sword in Iaidō. While I don’t doubt that using sayabiki to exploit the conservation of angular momentum does allow a more powerful draw, I think that the primary reason for sayabiki is simple mechanics: if one does not retract the scabbard, then the sword will not come cleanly out of the scabbard mouth — if the sword comes out at all, then its cutting tip will damage the scabbard and indeed the Iaidōka’s hand!

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Breakfalls

Yesterday, and not for the first time, I was asked by a fellow-student at the dōjō for suggestions and exercises to develop breakfalls. I am no longer surprised by this question, for reasons that I’ll explain in a moment, but I am still very challenged by trying to answer it — or, more accurately, how to actually help improve someone’s falls in practice and not just in theory.

Around the beginning of August 2009, after I had been in LA for a few months, I encountered Erik, an Aikidōka with simply beautiful breakfalls. What was particularly amazing about them was how quiet they were. I could certainly take breakfalls at that time; what I couldn’t do was land with the softness and silence that Erik exhibited so naturally. I knew instantly that I wanted to steal this secret, not just because it looked cool, but because adopting a less bone-jarring method of falling would prolong my life in Aikidō.

Erik showed me a few exercises, very much drawn from the ukemi system of Donovan Waite Sensei. In all honesty, they had very little immediate effect. After 12–18 months, though, something slid into place and different breakfalls were “just happening” for me.

A few characteristics of these new, softer breakfalls, as they appear to me:

  1. First of all, a very strong feeling of going forward. This really is a forward roll in mid-air, with no bailing out to the side or rear in any way. This, of course, means having a sufficiently responsive body earlier in the technique so that my body is in the right place to take a safe fall at the right time.
  2. Usually, but not always, a very soft feeling in the arm that I’m going over, which is usually the one under nage’s control. I do not want stiffness there. The only exception that I can think of is when taking such a fall out of shihōnage: I do not tense my arm, but I have a much stronger feeling that there is some structure in my front arm in this situation.
  3. A very active rear arm. In my old, noisy, breakfalls, this would be the hand that does the “slapping out” against the ground to break my fall and save my torso from the main impact. In the new world, this hand still performs this function but it (a) gets to the ground much sooner than before, and (b) somehow “touches” the ground rather than “slapping” it — more like quickly establishing contact, with no rebound.
  4. Usually, but this doesn’t seem to be essential, landing with legs bent to something like 135° at the knee, rather than the straight 180° angle I was originally taught. This seems to ease impact stress on the feet.
  5. It feels very energy-efficient, and often opens up possibilities to recover quickly enough that I can reverse the technique on nage if he/she is slow in pinning me after the throw.

The end result is a breakfall that, on a good day, feels great to take and makes for very little noise or stress on the body. There’s still plenty for me to work on: I’m better on one side than the other, I definitely have bad days as well as good days, and I would still be nervous about taking such falls on less forgiving surfaces than tatami!

The question, though, I how well I can transmit this experience to those who want it for themselves. How to convey it? And can it be done without the long period of no appreciable change that I experienced?

Further notes on this topic to come as I experiment with teaching strategies.

Faith in the Basics

Over the last few weeks, covering the Thursday evening body art classes at the dōjō, I have deliberately restricted myself to teaching a very limited selection of techniques. These self-imposed restrictions are an attempt to solidify my basics as much as the other students’, and are somewhat inspired by tales of Dōshu’s classes in Hombu Dōjō in Japan.

After the warm-ups, ukemi exercises, and tai sabaki (typically gyaku hanmi katatedori tenkan with uke’s hand kept open to promote good contact), I typically select from the following techniques, performed from a single attack:

  • the “holy trinity” of pinning techniques: ikkyō, nikyō, and sankyō;
  • the “holy trinity” of throwing techniques: iriminage, kotegaeshi, and shihōnage.

It’s definitely interesting to follow this “roll dice for the attack and then follow the basic script” model. If nothing else, it shows how poorly understood the basics are. I definitely feel deficiencies, and I hear other students muttering the same things.