After getting some idea of the groundpath principle I went to training straight away and broke my Jo. (yeah thanks guys) This to me demonstrated that I was missing something in what I am doing and that i actually have bad technique, I was over using my right arm and drove straight through the middle of the Jo consequently breaking it. But heres the thing i could feel that there was a hell of a lot more potential in my body than what I was using.
Anyway, I think that you have already discovered a new way of testing by getting someone to push and pull on your arm, why not take it a step further and get someone to push in all different areas of your body?
With regards to the jo, I don't know exactly what you did so I won't comment except to say tell me more
I haven't discovered a new way of doing unbendable arm, I think that's always been there if you logically apply the principles taught. As my teacher often says. If you can do it one way and can think of other ways to do it. Do it. Why wouldn't you?
The whole point of all this is basically not to say Mike Sigman is wrong (he's not) but rather. Why do you need to do CMA exercises to develop this stuff when the exercises to do so are already in aikido? I'd bet that many of the people in aikido who don't know about these things probably do
know the exercises used to develop 'internal power', I find it difficult to believe that they wouldn't, after all Tohei Sensei was the chief instructor of the aikikai for many years and the founder did this stuff all the time, they simply forgot how important they were. But it's still there if you look for it I think. But for some reason people seem to want to go elsewhere.