In my previous post I asserted that a notation system must be able to describe the posture of the performer. It follows from there that we need to have a better idea about what we mean when we say "posture".
Most martial arts systems have a set of canonical stances, the existence of which I'm going to take as a given. We need not concern ourselves with the question of what, exactly, this set contains; it is sufficient to know that each stance has a label with which it can be uniquely identified. Stances, like strikes, are assumed to be atomic; the statement "performer in X stance" is assumed to need no further explanation.
"Posture", however, entails more than just providing information about what stance the performer is in. There's also the question of orientation i.e. what direction is the performer facing? Which brings us quite quickly to the question of coordinate systems and absolute vs. relative positioning.
Let's step back a moment and consider the fundamental purpose of this exercise, namely "describe forms better than English". Flipping through some of my manuals I see two themes when it comes to describing the orientation of the practitioner. Most of the time the orientation of the practitioner is given implicitly using relative coordinates e.g. "turn left", "turn right", "turn 180°". Less frequently there are instructions using absolute directions such as "face front" or "facing X o'clock",
It would seem, then, that there is a need for both absolute and relative positioning. It is necessary at the beginning of the form to provide some sort of absolute direction but, once an absolute position is established, all future orientations can be described using offsets from this initial position. This suggests the following features:
- The initial orientation of the performer is specified using absolute coordinates. The specific absolute coordinates are up to the user; they need only be sufficiently understood/defined within the context of any particular school.
- Transitions between postures are specified using relative offsets.
In order to specify relative coordinates we're going to need to adopt a specific coordinate system. W.r.t. atemi waza it seems like cylindrical coordinates make the most sense1 since typical changes in relative orientation can be described using a single number.
Stance and orientation are sufficient to describe a static posture, so the next item to consider is how to describe transitions between postures. Here are some examples taken from one of my manuals:
- Draw left foot into cat stance facing left.
- Right foot half-moons forward.
- Right foot steps into horse stance facing 9 o'clock.
- Right foot steps back pivot clockwise 180 degrees and draw into right cat stance facing 3 o'clock.
- Hop forward toward 1:30 o'clock on left leg, with right leg held in flamingo position.
- Step out with left foot, jump and pivot 180 degrees, landing in low right twist stance facing 3 o'clock.
My heart is filled with dread and despair... those last couple look devilishly difficult. I'm not particularly worried abou the jumping and turning; those things, I believe, can be described fairly succinctly. What's going to be hard to deal with are all the fiddly bits about foot/leg positioning. Might it be the case that written English is the best medium for conveying such instructions?
Let's look at the first item in detail. Given what we've already discussed I believe we can readily handle concepts such as "cat stance" and "facing left", but we don't as of yet have any way of designating the left foot or conveying the action "draw into". We definitely need a way to designate limbs in some fashion, but I'm doubtful at this point whether its necessary to be able to convey a concept as complicated as "draw into". It would be sufficient, at least for a first cut, if we could render something equivalent to "turn counter-clockwise 90° into left cat stance by moving the left foot".
Based on the above the notation system will need some means of conveying the following concepts:
- turn
- left/right (hand, foot, version of stance)
- clockwise/counterclockwise
- (Change in) position of dan tien (low/lower, high/raise, very high/jump, move forward/backward/left/right)
- Foot movement/involvement in transition between stances.
1 Whereas if we were describing throws spherical coordinates might be more apropriate.
