There should be a small amount of upper body rotation at the beginning of the swing on the forehand when you're hitting from the back of the court, but it's not as much as on the backhand side. If you hitting the ball in front of you then you're relying on weight transfer through your step to generate power rather than upper body rotation. Hope that makes sense?
David Moffat, 15:40, Friday 12th August 2016
Where does rotation feature in the swing these days? What is it that we are rotating?