The best nikyos I've felt induced collapse. There was no pain, just a switch flicking from off to on, and I went from stood up to not. Nikyo seems to present the body with a moment of peak pressure that convinces your body to try and get lower/underneath it. Pain isn't part of the equation, unless the duration increases and the pressure decreases.
This is my experience of nikajo in the Mugenjuku dojo here. There is non-painful pressure starting in your arm and all of a sudden your knee collapses. This is not in every nikajo applied here, but in some. It feels incredibly powerful because with pain, you always have the idea in the back of your head that if you could stand the pain, the technique wouldn't work. But this collapse seems to happen as a non-conscious reaction.
On the other hand...
The question is whether that "induced collapse" is a developed "Pavlovian" response to having enough done, um, with "feeling" prior. How many have shown a brand new student a nikkyo only to have them stare at you? In pain. Eyes watering. But completely oblivious to how to go down and relieve the pressure on their wrist.
This may also be true. I'm new, so it's not a Pavlovian response, but once you see what you are supposed to do, it changes the equation of what happens during the technique. In a similar way, there are other techniques in which if uke doesn't cooperate, he may end up with a broken arm. Does that mean that the "real" aikido needs uke's compliance or that the "real" aikido results in a broken arm?
I don't know the answer to that. However, it is instructive that (1) in another post
, there are several anecdotes relate nikyo with pain and (2) in this thread we have the report of someone receiving nikyo from Ueshiba with pain. Also, in Aikido Jinsei
, Shioda Gozo relates Ueshiba refusing to perform in front of the imperial family by saying that "real" aikido always results in the death of the opponent.
Yet again on the other hand, contra Keith Larman, I have demonstrated nikajo to someone who doesn't do martial arts and the person went down instantaneously like an experienced training partner. This person had intense pain (not my intention--I wasn't even expecting the technique to work!), but their automatic response to the pain was to try to escape in exactly the kihon form for uke. So who knows.