I'm not Aikikai, but I definitely don't cause pain in any technique.
1. It doesn't always work, and just pisses most people off.
2. It gives uke too much information about what I'm doing.
3. If I can get uke to lock himself up, why would I need/want to hurt him?
If you do not cause pain to anyone in your dojo how do you teach your students to respond to a powerful waza which pounds them through the floor?How do you prepare them for a powerful nikkyo which cranks the wrist? For myself I can testify that Nikkyo hurts like hell at least for me.Joe.