I feel that the main reason for golfers not improving their games as they would like is that they often focus on parts of the swing that are not the root of the problem.
This incorrect analysis of the swing often leads to corrections that in fact worsen the problem. The most common incorrect self-analysis is "I didn't keep my head down." This analysis leads to the technically incorrect correction of trying to keep the head still.
It may be true that the golfer's height has changed during the swing. This is something to be avoided but the correction is not keeping the head down or still. If the golfer's height changes during the swing it is due to a poor pivot motion of the entire body and not the movement of the head. The correction for the height changing during the swing is improving the body motion.
A similar misinterpretation is keeping the left arm straight. The golfer with a noticeably bent left arm tries simply to straighten it without addressing the reason for it bending. The reason for the left arm bending excessively is either that the golfer is trying to swing the club too high on the back swing or the arms are getting too flat: (too far behind the right shoulder).
The correction for a bent left arm is to first realize that many tour players actually bend their arm a little, and to also realize that unless you have great flexibility you should not swing the left arm above head height. To correct a bent left arm practice swinging the arm to shoulder height only and keep the hands in front of the right shoulder. Practice this and you will notice that the left arm maintains its full extension without any effort.
Terry Gingell is a PGA Class "A" Professional and can be reached at 690-7970.