Stages of the Golf Swing

In addition to the actual downward swing of a golf stroke into the ball, the take-back of the club before the shot and the follow through afterwards are just as important. Understanding the roles of all three stages of the golf swing will help you score better and enjoy the game more.

Backswing

The backswing (or take-back) portion of a golf swing is an eccentric muscle contraction (you extend muscles). This is where you build up and store energy during the stroke for your swing into the ball. Eccentric muscle contractions create more energy than concentric muscles contractions (you contract muscles) used in the forward swing, so it's important to take a full backswing for maximum club head speed going forward.
During the backswing, a violent motion made in an attempt to create more energy can lead to poor body positioning during the forward swing. This is why a smooth, steady backswing which does not jerk the torso out of alignment with the initial stance, is important. If you've heard of keeping a "quiet belt," this refers to keeping your elbows in during your initial backswing to keep them working in unison with your torso. This will keep your legs from moving incorrectly, as well as keep you aligned with your desired swing path.

Forward Swing

The forward swing is a concentric muscle contraction during which you release the power you have created and stored in your arms during the backswing. Leading slightly with the hip allows you to break the kinetic chain of events (the various coordinated movements that make up a golf swing) at their final link, creating the internal shoulder rotation that provides most of your club head speed at impact. Leading with your hip allows you to keep your elbows in, and "drags" or accelerates your arms into the shot.

Follow Through

The follow through adds no power, spin, slice, trajectory or any other effect to a golf shot. This is because the follow through happens after you hit the ball. So why is a full follow through stressed so much by golf teachers?
Imagine that two runners of equal height and speed are running a foot race. One gets to run past the finish line at the end of the race, while the other has to stop on the finish line. Who is more likely to win? The runner who gets to run past the finish line, because he won't have to slow down before the finish line to stop at the finish line. If you do not swing through your golf stroke, you will have to decelerate prior to striking the ball. This is why many golf teachers teach you to swing through the ball, or to hit "past" the ball.