Re: Ikeda Sensei Demos of Ki
Ikeda sensei has a whole list of pointers which he refers to often.
"Make unity" is one.
"This works" "this doesn't " is another , notice that usually when he says this , his posture does not change. What is is that he switches on / off without changing things overtly? If you feel the demo, it's a shift between a lack of solidity (doen not work) vs solid coupling of forces in which you can feel the push of your grab being met somewhere. It's a demo for feeling it; as Uke you should be giving a clean steady force so you can feel how it gets changed
"Shift your insides" to move your partner; once you are connected via kokyu you are relying on your mind directed sense of how the forces collide , the skill is to be able to harness that ability to change the sum of pushes (balance!) into a direction of your choice. It is not an imaginary thing; your body has to do stuff to make it happen. There's a logic to the shift; the forces are best handled from your middle , not from the extremities, or the connection is broken and so on.
One thing is sure; you should not be pretending to feel things as Uke or Nage; It's not about imagining the other guy moving, and the uke imagining he's being moved. It's a physical thing; you should feel it. Aikido ukemi doest require you to use your biceps or triceps in isolation when doing a roll; as Nage you have to be able to move in a similarly connected fashion, keeping the "path to the ground" , using it to move your uke,