Many golfers struggle with hip rotation, backswing positions and hip extensions.
The biggest problems with amateur golfers is an early hip rotation and over the top move which is caused by a right shoulder and elbow move not a over rotational movement.
This video discusses how to stop an early hip extension in the golf swing. The answer is quite simple and learning how to rotate the body through the golf ball correctly, matching this up with your style of golf swing and you have a great chance of creating a great rotational golf swing on plane.