Still, it is interesting to note that Mori Shihan who was-according to his webpage-the last Ushi-deshi for Shioda sensei and the fastest to 7th Dan in Yoshinkan seems to be applying Nikyo is a way that is utilizing at least some pain if the Uke's face and body language are any indicator. I don't know if I would say that he is utilizing the lowest form of martial technique and I can't speak to any involvement he may have had with Tae Kwon Do .However, he just seems to me to be really good. Perhaps, O-sensei was well.......O-sensei and not doing exactly what O-sensei did can still be really really good too.....................even nikyo..

http://youtu.be/ugsS2_Z0wpA

Train Hard,
Jason

I am studying Yoshinkan. We are learning nikajo like this:
http://www.youtube.com/watch?v=QchlmrPnidA
We are told that nikajo should not be painful in the wrist. This is a difficult effect to produce, but as uke, I have felt times when the only thing I noticed was my hip and knee collapsing--no pain response.