There is currently much writing and discussion going on in the world of golf instruction focused on Swing Plane.  We have also received many questions from Natural Golf devotees regarding Jim Hardy's theory pertaining to his book "The Plane Truth" and if his recommended swing mechanics for the "one plane swing" apply to Natural Golfers. 
This article will clarify Natural Golf's definition of Single Plane so you can continue down a simple path to cheap golf equipment better golf. First and foremost, Natural Golf uses the shaft of the golf club to define the plane of the swing. We say a swing is single plane when the shaft angle at address matches the shaft angle at impact. Ideally, the shaft would stay on this inclined plane throughout the entire swing; much like the shaft movement created by the golf club testing machine, Iron Byron, used by the USGA.  And, much like the shaft movement of a club as swung by Moe Norman (pictured above). By starting at address with your arms aligned with the clubshaft, you can swing back and forward on virtually the same swing path or on a single plane, we believe there is no simpler move in golf. It mimics the direct strike of driving a nail with a hammer, the way you hold the tool aligns your arm with the handle and a single plane motion is the most natural and most direct motion to use. Jim Hardy defines a swing as "one plane" when the shoulders and lead arm are on the same plane at the top of the backswing. While he references a difference in setup between one and two plane swings, he does not use shaft angle as the criteria. Because the two methods use different criteria to define One or Single Plane, the swing mechanics of each method are not completely interchangeable. Using our Natural Hold on the club automatically aligns your arms with the clubshaft at address. Swinging the club on an arc around your body with your arms will deliver the club through impact with a square clubface sending the ball to your target. By paying close attention to Taylormade R11 Rescue Hybrid our Single Plane Setup, you will simply have to focus your attention on the direction of the forward swing path to create a Single Plane Swing. Naturalness dictates that club path control is directed by the arms and hands.  Because of our Single Plane Setup, your body will move to accommodate the direction you choose to move your arms.  There will be some shoulder turn in the backswing as your arms move the club on a Single Plane and some shoulder turn in the forward swing to accommodate this same plane (swing) direction.  Your weight will transfer from trail foot to lead foot also; this inherent body motion will amplify the speed of your arm swing to increase power.  The faster you move the club with your arms the more your body will move in accommodation.  Trying to add body motion to create arm speed will almost always throw the clubshaft off the Single Plane direction. 
Think of it this way...if you want to drive a nail harder, do you try to turn your shoulders more, or drive your hips?  Probably not, at least not consciously...you simply move the hammer faster with your arm, any extra body motion occurs in accommodation of your intended arm speed. It's a lot like throwing a ball.  When you intend to throw farther, you move your arm faster and in accommodation, your body moves in anticipation and support of your intent to increase arm speed. For example, when you throw really far you will most likely take a step in the direction of the throw just prior to accelerating your arm in that direction. The step toward the target and the body motion it entails occur because of your intent to throw far using your arm. Moe Norman showed us a simple setup that produced a simple and remarkably repeatable swing.  Natural Golf follows his lead with our Natural Hold that leads to a Single Plane Setup so we can use the most direct strike in golf...a Single Plane Swing. Keep it simple folks! Ken