DH

Tim
If you are interested in the Japanese perspective look for references to training involving breathwork or "breath-power". You will hear the term breath-work brought up here or there by the some of the old guard. There is a reason breathwork is connected to fascia work. Also look for references to "long muscle." There are two schools I know of which used this terminology for fascia. It showed up again recently at Aikido journal in an older article some forumite referred to in a link. I'd have to find it. There is a discussion of bone thickening and skin toughening as well in another article by a guy who trained DR. I think he talked about a broken arm and an X-ray showing thickening. For other references you have also a picture of Takeda's son doing In/yo ho breathwork exercises in a recent book out. It only gives a cursory overview of "feeling" the hands being drawn-in and then pushed-out. Naturally, it contains no details of; what, is doing what, and why breathing is involved in the first place. Good luck researching though, a friend of mine is in Japan right now training, and decided to ask some detailed questions about some things. It didn't go well. I suspect these things will almost always be held close to the vest, denied, and generally not spoken about. As Sagawa said "Teaching these things to foreigners would give them an advantage." How pervasive is it? Who knows. Its very existence gets denied.
I think you might have better luck talkng to PT's, message therapists, and bodywork people than Docs. They see what fascia does on the recovery end of things day-to-day from injury and lack of use, and how hard it is to rework it at a natural level. Stands to reason it is connected and it is tough stuff. So strengthening it and making it work as a whole interconnected system seems rational on the surface-pun intended.