WHAT IS FLAT SHOULDER PLANE?
Flat shoulder plane or turn describes the angle of the shoulders as the golfer turns to the top of the backswing. When the golfer addresses the ball, the spine is tilted due to the forward bend of the hips to allow you to get into the correct setup position. The ideal swing requires the shoulders to move perpendicular to the tilt of the spine on the backswing. A flat shoulder plane is when the shoulders turn on a more horizontal plane than the axis of the original spine angle. This causes the club to be out of position on the backswing and changes the original spine angles on the downswing, reducing efficiency of the motion. As a result, the golfer usually compensates on the downswing with the body or hands to square the club face. This can also cause a loss of power in the swing as well as cause inconsistent ball striking.
Articles and Swing Drills for Flat Shoulder Plane