The movement of the knees, though seldom discussed, is vital to hitting good shots. The knees provide stability, back and through, and help ensure you hit the ball with the center of the clubface.
Let's start with the front knee. On the backswing, it should remain flexed and pointing at or behind the ball. This allows you to make a good hip turn and complete the backswing by fully shifting to your right side. On the downswing, the front knee should rotate a little toward the target, but more important, it has to straighten to brace the body for the hit.
The back knee also should remain flexed as you go back. This prevents the body from swaying away from the target and out of position for impact. The back knee should start in a kicked-in position, pointing at the ball, and pretty much stay that way until you swing down. That's when it moves toward the ball before ending up tucked behind the front knee.
A good drill to help train better knee action is one I saw LPGA great Mickey Wright demonstrate in this magazine many years ago. Put a golf ball under the outside of your back foot and make some practice swings. This helps give you a feel for how to prevent that backswing sway that ruins so many shots. Give it a try, and your impact will improve.
ELEMENTARY WATSON I really like the "kicked-in" position of the back knee when it comes to chipping. It helps you hit down on the ball. Start with that knee leaning toward the target, then lean it more as you swing down. You'll keep the swing's low point in front of the ball for crisp contact.