A good forward shaft lean on impact is a bi product of getting some other key things in place in the swing. Using an impact bag can give you a stationary feeling of impact but if you don't have these other important aspects happening in your swing you will never get into the correct impact position. It's my belief that getting a good forward shaft lean on impact is created by 3 things....
1) Maintaining a tilt of the spine to the right at the top of the back swing (Face on View)
If your spine tilts to the left at the top of the swing you will lose your body shape and you will have to cast the club from the top to widen the downswing arc to stop you from topping the ball
2) A good lag on the downswing. Once you've got the correct body shape at the top a good lag on the way down will help you to get the forward shaft lean on impact.
3) Maintain your posture angles through impact If you straighten your spine angle (Down the line view) you will lose your lag and flip the club on impact as you will have to extend your right elbow and wrist too early to avoid topping the ball.
Any thoughts or comments?