Greg Steckel wrote:
In addition, I also try to differentiate the terms Irimi/tenkan and omote/ura by defining Irimi/tenkan as types of movements, and Omote/Ura as placements, in relation to the position of Uke.
Some folks say irimi movements are for omote techniques and tenkan movements for ura techniques. Although this may be generally true, there are irimi movements to place you in uke's ura and tenkan movements done in omote. Actually, I have found all techniques to have some form of both.
I have similar opinions on the subject and use of these terms. As a beginner I was originally confused because the distinctions between these terms wasn't made clear to me. In a Ki-Society orientated dojo they would say such things as ikkyo irimi or ikkyo tenkan, but when I went to an aikikai dojo the same techniques were described as ikkyo omote or ikkyo ura, so for a while I thought the terms were completely interchangeable. As was said in many cases the terms can be interchanged because the positioning corresponds with the movements employed in the technique, but I think it is best to differentiate because there are so many techniques that are omote techniques that use tenkan movements and other such exceptions. And as mentioned above in reality one will discover you can't really do tenkan without some irimi and vice-versa.