Thank you Janet. Right... LOCK... need not mean pain must be there for it to be effective. Matt yes and to a properly compliant Uke outside the dojo as well.
Actually in the dojo I like for my partners to sometimes apply the lock tot he point of pain compliance so that I can fully experience the technique and so that they can be sure that if they were to need it they could get it.
What I'm saying is what others have said. Pain is in addition to an already effective technique, when it becomes necessary... with a non-compliant uke .
The technique should not rely on pain to be effective. For instance Yonkyo simply does not work well on me on my right side. I have a fellow student who it does not work on at all. And I've had locks put on me that totally dropped and/or immobilized me without me feeling the least bit of pain. And I am not always a "properly compliant" Uke. Since I am still learning, and since I have fellow students and a couple of senseis who like having me set up and give some resistance form time to time.