Interesting. I note that no one has really discussed 'what is elbow power' in this thread.
As a historical tidbit, there is a concept of "hiji no ri" or "elbow power" (perhaps more accurately, 'the principle of the elbow') in Judo. An aquientance of mine (who's trained with both Sam Chin and Akuzawa, as well as being Dan ranked in Tomiki aikido) has mentioned that 'elbow management' is a hot topic in those arts. Considering something like Wing Chun (which seems to have a very interesting way of using the elbows / arms), I think something like this might be a fruitful discussion.
I tried discussing it once and left some descriptions and hints on the table. No one really got it and responded with anything substantial, and to date I haven't seen a real description of;
What it is
How it works
Why it has such a profound meaning in aiki arts
I have no more interesting in arguing about it, so I just do it in person.
In regards to Ukemi; it's my understanding that certain hard chi-gung exercises involve hitting oneself (lightly!) in order to 'spread the chi'.
There are some very well respected Internal guys who don't think much of that model and claim it isn't necessary. I think it does and there are ways to incorporate it in training to toughen you without doing damage
Actually, if you think about it, something like a side-break fall could serve a similar body conditioning purpose. I also realize that Kuroda has an interesting article on the use of ukemi (or rather, ukimi) and how it relates to his internal training.
In other words, ukemi training (as it is, without turning into bogyo) might serve a good purpose
I disagree with Kuroda about a number of things Kuroda does-including his much vaunted weapon work. As I described right here years ago, I later found out it did in fact fail to demonstrate power when put to the test. And yes...I know some big names love his stuff. But those big names don't see what I see and nor can do what I do. And I think he is wrong about Ukemi as well and that
can be proved as well.
This is either a deep topic or it isn't, and if it is deep, than it is complex, and if that is the case than there people who have developed certain parts and pieces, and others who are, well, more complete. We are engaging in a process, sometimes a very surprising one, at founding out just who is who. This is far more accepted, even expected, in the Chinese arts more than the Japanese. Sometimes it doesn't make people feel comfortable, but I think that in the end, truth does that. It also leads us into new realizations and understandings in our training that will lead us forward.