For all the work golfers put into getting the club and body in the right position during the backswing, it's easy to overlook the importance of transitioning from the backswing to the downswing. It's particularly helpful, for example, to know which move should trigger the beginning of the downswing.
Completing the Backswing
Before initiating the downswing, you must fully complete the backswing. Along with setting the club at the top of the takeaway, you need to make a full shoulder turn so as to have your upper back pointed toward the target. Your hips should also turn away from the target, but only about half as much as the shoulders, golfing legend Ben Hogan wrote in his book "Five Lessons."
Arms and Shoulders
You might intuitively believe that, because the club is the instrument striking the ball, the arms and shoulders should initiate the downswing. Beginning the downswing this way, however, will throw the entire swing out of sync and could lead to the ball going any number of different places, instructor Glenn Deck writes for "Golf" magazine. Among the many problems caused with an arm-starting downswing is an early release of the hands, which results in the club face losing proper orientation.
Lead With the Hip
Your downswing must be initiated by the left hip, Deck instructs. By turning that hip toward the target, a physical sequence is started which not only helps to maintain the proper club-face angle, but also to create the club-head speed necessary to generate power. It may be easiest to think of this motion as the uncoiling of the body through the ball and toward the target.
Hogan identifies the desired sequence of events in a downswing as the hip move followed by the hands and arms dropping into place -- which establishes the new swing plane for the downswing. The uncoiling of the shoulders must wait until the hips have started moving forward and the club is in the lower position. If the shoulders begin turning too early, the swing path of the club will be compromised, leading to errant shots.