A common problem for many golfers when they swing is they lose the flex in their trail or back knee. The flex in this knee helps the golfer maintain proper balance, posture, support, and allows the golfer to swing the club on a better plane.

Losing the flex in the trail knee causes golfers to reverse pivot, sway, stand to upright in the backswing, or creates excessive motion in the golf swing. A common compensation is either to come over the top or cast the club in an attempt to square the clubface at impact.

Two drills can help with this problem.

1. Assume your address position. Place the club across your shoulders holding the shaft at each end. From this start position look at your back knee and pay attention to the amount your knee is flexed. Now turn your chest until it faces away from your target. Stop and check the flex in the back knee. Did the flex in your knee change or stay the same? Done properly the flex in the back knee should have stayed the same.
2. Hit golf balls with your feet together using three quarter swings. While doing so pay extra attention to your trail knee and maintain its flex to the top of your backswing.

Keep that flex in the trail back the same to help improve your ball striking.