Here is the whole backswing for a one-plane swing. From your bent over address position, the arms on the takeaway move in so that the right elbow is working behind you and the left arm is more across the chest. From here up to the top the left arm continues across the chest as the right arm folds and lets the club cock on-plane. What you have to be careful of is that when you go to set it on-plane that the right elbow does not get out in front of you, you want to keep the right elbow behind you. So the left arm as it gets to the top will be right across the shoulder plane at the top. As a matter of fact, a good sensation as you are going back is to feel like you are going to throw something behind you, which I will demonstrate in just a minute with my golf club. Keep in mind for your two-plane swing, those of you who swing more upright, your swing is going to be going more straight back away from the target line and up as you are turning. So the one-plane is more around and behind you, across the chest. Here is that move I was just talking about, I am going to take my club and I am going to toss it right behind me. You will notice that my right elbow starts to lead the throw and then the arm lets it go. That is the sensation you want with your right arm your one-plane backswing. You can really hit it from there.