I'm going first to go back to the wave, or the whip, analogy for explaining the power generation in Hiroo Mochizuki's pedagogy.
The wave has an inverse relationship between amplitude and frequency.
A large wave has a large amplitude and a low frequency. It is visible.
A short wave is the opposite. It is almost not visible.
Visible, here, means that you have the time to understand what you are seeing because of the slow speed and the large amplitude motion.
Invisible means that you don't have the time to understand the images because of the high speed and very low amplitude motion.
So, H.Mochizuki starts with the large wave so as to facilitate the demo of what body parts exactly are moving, and how momentum is transmitted through the whole body.
There is a specific sequential body coordination in order to produce ascending or descending waves in the sagittal and frontal planes.
Both direction waves can also be combined into one cyclic "wheel motion" (circling up/down or down/up) in any plane.
The large wave can be applied in combat, particularly for the throws.
The short waves are more used for atemi, and for weapons manipulation.
The short wave isn't no more really a "wave", as it can't be visually seen like that (you can't see a clear waving, with up and down curves travelling, in alternance, through the body).
H. Mochizuki calls then it a "vibration".
But this explosive motion is supposed to be the same pattern as the "undulation".
Frequency is very high and amplitude is very low, thus the eyes only see a kind of shaking, or a vibration of the whole body.
It all seems to appear in simultaneity, rather like a sequencial motion because of the high speed.
For the purpose of pedagogy, the large undulation can be exercized very slowly, so as to let the time to the body awareness to be impressed (awareness is rather limited).
It means that under these special exercices conditions, you can really follow what is moving and how.
But of course, for combat application, be it as a sequencial motion (imagine an explosive Judo throw for example), or as a quasi-(or true) simultaneous motion, the wave becomes very quick, hence a vibration.
I personally think that the wave analogy in Yoseikan Budo has to be carefully explained in order to clarify what "sequencial" and what "simultaneous" words actually mean.
When considering the fact that a body wave has some amplitude (meaning that it contains "dynamic ups and downs" travelling through the body), it is then very important to understand that the "down body parts" are NOT totally relaxed, like being completely passively waiting for the momentum.
[Please, excuse my poor language!]
Yes, there is some degree of "passivity" in order to let the primary impulse coordinate the whole body parts.
But the whole body is still actively maintaining an aligned structure (tonic function), that is going to be further dynamized by the impulse.
Only then, the impulse can be precisely channeled (axially) to the intended contact point.
If you represent the whole body as a dynamic alignement of several blocks (tensional blocks, not compressive blocks), you can visualize what exactly is this body wave.
And you can understand why the use of the whip or the wave analogy.
You can see the body as composed by 3 general articulated blocks:
The "central block" is that one of the trunk/head, and it is there that originates the primary impulse.
The trunk itself can sub-divided into 5 components:
- the pelvis
- the abdomino-lumbar
- the thorax
- the head
- and the full spine
Thanks to this simplified, yet precisely articulated, body model, you can initiate a very precise body wave.
And also, you can see that by initiating only one trunk impulse, it is going to immediately affect the whole trunk/head dynamic alignement.
It can't be truly a "sequential motion", because if you move one "block" (by closing/opening), it is the whole spine (and other blocks) that undulates altogether.
The critical element is then the coordination (and timing) of this impulse through the various "body blocks".
Essentially, it means that there is NOT fixed center of motion, and that periphery is as much important for re-cycling the momentum (fourth/back).
Once there is a primary impulse, you have to make it continuously "alive" (if you want), by re-cycling it like in a closed circuit.
This re-cycling of momentum is particularly critical thanks to the spine.
For example, there is no relaxed chest wave possible without a corresponding head wave, a corresponding abdomino-lumbar wave, and a corresponding pelvic wave.
However, it is possible to make a big chest wave but simultaneously "freeze" the head wave at the top...
Momentum is then stopped at the top.
Stopping the momentum is NOT a problem if you can maintain the aligned structure.
Potential motion is still available at will.
You then simply release the "body blocks", as if motion was just beeing kept in "suspension" at the top (or in "compression" at the bottom if this is the case), waiting for this release.
The important element is the wave itself motion between these two polarities.
Solar plexus is the center of the closing/opening of the trunk (between abdomino-lumbar/thorax which corresponds to vertebra T8):
- this dynamic center allows the belly to be "full" and the chest to be "empty".
But this solar plexus center has to be synchronized with each extremities of the bow, the pelvis and the head.
Only then, the spine can function like a bow (compression/extension).
Even turning is possible without a thoracic vertebra rotation, but only just cervical rotation.
It is just a closing/opening of the trunk around the solar plexus/T8 into a diagonal.
But it requires some trunk mobility and relaxation.
It also requires a different pattern coordination than the usual.
Finally, I agree with many who have said that the wave model is not new, nor unique to Hiroo Mochizuki. Others have discovered it as well.
At the same time, each one method is specific, and so Yoseikan Budo has its unique savour.
I, for example, palso articularly appreciate the Kenji Tokitsu's method (Tokitsu Ryu), and the Kajo Tsuboi 's method (Kiryuho), among others.