When I irimi in and atemi uke should be forced back my problem is I can,t keep him going back.any help is appreciated
Ideally you meet an attack with the timing that put attacker hand, left and right shoulder on the same line or little behind the line of his shoulders. And then you are shifting you weight lightly forward. That happens in the first moment of the contact and should shape his backbone to the back. It means that the direction of unbalancing is to his third point behind his back. Continue to stretch his arm to this point while you are doing shihonage. You have to maintain not only the contact with his attacking arm, but stretch and lock this arm
all the time during the turn of your hips. His arm must be stretched(you can put your elbow under his elbow) and in horizontal
position while you pivoting. That maintains unbalancing.