Let’s discuss the backswing. The purpose of the backswing is to get the body in the proper position to move forward, bottom line. Most golfers never get into this position which can lead to a long list of swing flaws. You may notice as hard as you try you cannot transfer your weight. Your left arm bends or breaks down, your right elbow flies and you don’t have control of the golf club. Many of you can relate to this. The good news is one simple change can make all these problems go away.
The key factor in the backswing is the angle of the shaft. This position, in most cases, dictates what position your arms and body are going to be in when you start your forward movement. Most golfers swing the club too steep, creating a vertical shaft angle. (see photo) 
This position can set a chain reaction. This vertical position will cause the left arm to bend forcing the right arm to fly and separate the arms. The arms now cannot extend. Without arm extension, the weight cannot transfer which means your turn is limited and you are in a weak, unbalanced position. Notice the arrow on the shaft. If you were to simply let the club fall from this positoin it would fall on the path of the arrow away from the body. This path creates an arm swing limiting what the body can now do. This is the major contributor to an outside-to-in swing path.
In the picture below, the shaft is in the proper position going back. You can see I am in a much more athletic position. The shaft angle has placed my arms properly allowoing them to extend and remain much closer together. The arm extension allows the body to shift properly allowing you to get into a powerful and balanced position. The position the shaft is in if you were to let it fall, would drop behind the hands, engage the body, and allow the club to be propelled using the body and arms toward the target.
