Many golfers believe that a long backswing, in which there is much turning of the shoulders and hips, is an indication of good coiling. However, in most cases it is not. In true or effective coiling there should be maximal rotation of the shoulders with minimal rotation of the hips.
This means that there should be a major separation between these body parts so that the midsection muscles undergo a strong eccentric stretch. You should feel tension not only in the midsection and lower back, but in the hips as well. This applies mainly to the medial rotation muscles of the left hip joint.
In other words, when you have true coiling, there will be great tension in the muscles ready to be released in the downswing. Merely having a full turn of the body (hips and shoulders) does not ensure the tension that is needed in the muscles to produce a powerful downswing. There are several important factors involved here.
First and most important in achieving a tight coil, is to keep pressure on the inside of the rear foot during the backswing and to maintain a bent rear leg. If you allow your weight to roll over to the mid or outside of the rear foot you will not be able to achieve a tight coil.
Second, you should not straighten the rear leg since it allows for a greater hip turn to the rear. This takes away from the tensing of the abdominals as needed when you execute the shoulder turn. The greater the separation between the hip and the shoulder turn, the greater will be the tension and the more power you will be able to exhibit on the downswing.
For a good coiling action, it is important that you limit the amount of rearward rotation of the hips. The more the hips rotate to the rear, the less the build up of tension in the abdominal oblique muscles which play the major role in rotating the shoulders forward in the downswing. Keep in mind that this shoulder rotation is a major source of power — 30 to 50% of the total generated — in the golf swing.
Third, by keeping a stable base (lower body) and rotating the shoulders independently, you can get the greatest amount of effective coiling. This requires great flexibility in the midsection, more specifically in the waist. One of the best exercises to ensure you have this flexibility is the reverse trunk twist.
By adhering to these three criteria you will get the necessary tension of the hip, and midsection muscles that is needed to rotate the hips and shoulders in sequence, around the front leg after your weight has shifted forward. You will have much more force in the downswing. Without the prior tension from effective coiling, however, you’ll have a weak hit., or a hit in which you could have had much more power.
See Explosive Golf for more information on coiling and the exercises you can do to ensure an effective coiling action to generate maximum force in the downswing.