Duval Culpepper wrote:
By turn away, do you mean kaiten?
Not a full kaiten, more like a half turn (turn body 90 degrees) which will allow you to break his balance to one side and get his forearm into your armpit, from which you can leverage down upon the elbow with the side of your body by sinking your weight. If you want to you can still apply the nikkyo on his wrist with your other hand as his arm is trapped under your armpit, which just adds more leverage to the technique.
The Yoshinkan does this technique a lot, Judoka do it too from the ground mostly. Can't remember the name at the moment though, the Shodokan version is called Waki Gatame, but is more of a forearm lock than a leverage on the elbow. An idea of it can be seen here, http://www.ttac.0catch.com/hiji.htm
Of course you can just do a full tenkan and just splat him face first on the floor, or take his pushing hand, and his balance along with it, pivot the opposite direction and do koteageshi.
Sort of like shown here http://www.ttac.0catch.com/tekubi.htm
There are a few options to a one armed puch imo.