Keeping the head level should help. Remember that it is OK to have some lateral movement of the head, but not OK to have it moving up and down. I know Nicklaus talked of a spike driven through the back staking one out so that the head was like in a vice. Today, most instruction says keep the head steady, but some lateral movement is OK. Just be sure that at impact, your head has not passed its at address position. After impact your head can move more foward because the ball is on its way by then.
Just remembered a major worm burner cause. Suppose as you go back with your swing that you let your weight shift outside your back foot. Now it will be just about impossible to get your head (and weight) back to at address position which is about the same as it should be at impact. You have effectively moved the bottom of your swing to the right (for right handed golfer) of where it was at address. This will cause a few possibilities which are not good. If you do not raise your head or release your swing early, you will hit a fat shot. If you instinctively raise up or release your swing early, the leading edge of the club hits the ball higher than it should with a worm-burner a likely result. Solution: Never allow the weight to escape outside your feet during your swing.
Sincerely , Cypressperch
