Raul Rodrigo wrote:
While we're on the topic of books that give you an idea of how to use the jin/kokyu forces, I'd like to asks Mike S about Shioda's Total Aikido. At some point he says the source of power in aikido is the big toe; when you fix the big toe on the ground, power flows into the leg. It was that sentence that started me thinking about what is apparently called "groundpath" and to pay attention to what happens when I do the boat rowing exercise. I'd just like to be clear: is Shioda in fact referring to the groundpath?
Well, that's a good question. My personal idiosyncracy is to split the wholistic/aggregate meaning of "Ki" into 2 things: the kokyu/groundpath/gravity forces and the "connectedness"/fascia forces. Technically, I'm on solid ground because the forces can be always looked at as being 2-part. Open-Close. Extend-Contract. Power through the skeleton from the hara; power returning to the hara through the "connectedness"/fascia. The last example has a lot to do with what the "ki of heaven" and the "ki of earth" are.
For an overly simple example, think of a push with one hand going straight out to the front of the body. Ideally instead of just using the muscles to push the hand out, you should channel (using body and mind coordinated) the support of the ground to the hand through the skeleton (but some use of the fascia is always there as an assist). Pulling the hand back to the body (i.e., completing the cycle of the whole movement) would involve using the forces along the "connectedness"/fascia (plus some groundpath, necessarily, for parts of the motion).
So what I'm saying is that there are always 2 components to any "natural" body-power movement... the forces through the skeleton and the forces on the body cover (to keep it simple).
The short answer, the one that will mislead you if I do it, to your question is "yes". The long answer is that it's both of the factors I mentioned above, but the fascia part is probably as important, if not more important, than just the groundpath.
Incidentally, that concept of power coming from the big toe is a pretty ancient perspective and almost undoubtedly comes to Aikido via sword training, because of the correct Aikido stance. If you want to see a telling comment that has a lot to do (not fully, though) with this concept, take a look in Lam Kam Chuen's "Way of Power" book. Surprisingly, he blabs a little bit about how this is done, although he leaves out part of it.