Timothy Walters Kleinert
... it's likely a big piece of a complex system. I'll lay out the case as I see it, and everyone can be their own judge.
Simpler than that in many ways, I would say, although complex to understand. But read on and decide, as you say, for yourself.
Timothy Walters Kleinert
---I think it comes down to one simple question: How does one stabilize the body?
In other words, what bio-mechanic is being used to hold/move the body? We all know that force is transferred through the skeleton, but how is the skeleton held in place? ... There has to be some sort of bio-mechanical process at work in the body.
There are two typical ways of analyzing static structural stability. First, thrust and load vectors of force and reaction. Second, the method of moments. Of the two, the method of moments generally involves less computation. This is a starting point if we posit some adaptive controller component in the system (which clearly is the case.) One would expect the system to take the computationally conservative solution (on evolutionary grounds, if nothing else).
I am going to put your four points in one big pile and show they all relate.
Timothy Walters Kleinert
1. "Internal" and "external" use the same biomechanics, the difference is just a matter of technique.
2. Internal movement is simply an unusually efficient arrangement of normal musculature, facilitated by various mental images.
3. Internal movement depends on a hyper-development of postural muscles.
4. Fascial Tensegrity
I will start with three items that are NOT unique to aikido in the realm of fighting but unique to it in its intentional direction toward those aspects as the basis for its strategic approach. Other approaches will necessarily start at item four and in intentional mimicry of that basis from training (see item 8) but the real thing I would maintain is the natural system unchained. But do consider the importance of them to the "True Budo is love" concept. It ain't daisies and moonlight walks.
Consider this type of biomechanical progression:
1) a threat to a loved one
2) oxytocin aggression hormone dump (read up on it -- cool stuff completely
different effect from pure adrenal surge -- and it can dictate adrenal surge through the HPA axis, as needed)
3) Smooth myofascial tissues contract in response making the body and limbs into taut drum-like tube.
4) Training has caused the body (as this hormonal surge takes hold) into certain postural forms that are then set into relative form like a stiffened "Jello," if you will. Anybody who has raked leaves or shovelled for a good while has had this kind of "set" occur in their hands from another mechanism (histamine, likely) evoking the same tissue response.
5) the body has just become a unified field for any vibration moving through it because the limb discontinuities are overridden by the continuous and relatively solidified "suit" therefore structural change information travels at the speed of sound in water ~1500 fps vice neural transmission speed ~60 fps. Adaptive response rates can therefor outstrip conscious counteraction by two orders of magnitude -- That's a lot of lead time against the four guys on the end of a jo.
6) The form of the limbs, though relatively fixed (e.g. tegatana) allows the translation of moments into different axes which changes the effect of action upon the structure without directly opposing it with articulated "local" muscular action. Such a mechanism altering length in two complementary axes, simultaneously (the principle or mode of asagao
(watch the video of the Morning Glory (asagao
7) Under hormonal surge these alterations of the static moment of the body can only be driven from the core to "stir" the stiffened Jello to transmit its "jiggle" unimpeded from one end of the structure to the other. That's why it is not that muscle is an active "local mover" -- it is a passive local re-transmitter.
8) in training we find ways to mimic this hormonal condition more or less voluntarily. A good example being the no-inch punch -- in essence hitting with the whole mass of the jello behind a coordinated delivery of a half a jiggle (a single jig- without the -gle, so to speak) But in a true threat action where this hormone cascade functions, the action achieved is neither voluntarily decided or contrived, nor even possible of being constrained in action.
9) A moment is written as a half -circular arrow -- the beginning of a rotation -- which is what it is -- a rotational potential
. If all the body is doing is resolving induced moments, then the thing I propose makes perfect sense. The (high frequency) impulse of the contact is transmitted (via a vibration -- a rotation-in-place) long before the structure as a whole begins an unrecoverable rotation. This is an adaptive signal telling all the needed information about location signa nd magnitude of the instantaneous change in total moment, running well ahead of the induced structural change -- all it needs is a responsive system, waiting to use it. This body is an an analog computer assessing the virtual work of the moment sensed and then simply compensating to bring it to zero.