Hip turn on the backswing

People teach this restricted hip action on the backswing, which is not optimal based on human biomechanics. Allow that right knee to straighten (not lock, just straighten), and the left knee to flex allowing the heel to rise off of the ground as the knee and right hip pull it to do so. The left heel will not spin, but lift.

This is a proper hip turn on the backswing, based on my experience with biomechanics and kinesiology. I'm not certified as an expert, but I have studied thoroughly for three years human anatomy and motion.

This will save your back tons of pain.

Straight right leg is an immediate hook for me. No chance I'm going that route again

If this is what you do, then more power to you. But you are very far from the truth.

My understanding is straightening the right leg and bending the left knee in, heel up on the backswing has as much to do with flexibility as anything else. Older players may do this just to get a little more turn since you tend to lose flexibility as you get older. If this motion works though, who cares. That's all that matters. It worked for Nicklaus, Payne Stewart and Bubba.