Faults: What is Wrong
When the upper body moves faster than the lower body in the downswing, it can create many faults. Here are 2 of the most common.
1) As a result of the upper body rotating too fast, the arms will get outside the correct swing plane in the downswing. From this position, 2 different things could happen.
- Most commonly, you will continue on an outside swing path in the downswing, creating an impact zone where the club head moves from Out–To-In. If the player squares the clubface to this path, the ball will start left and finish left (pull), and if the players opens the clubface to this path, it will create a slice shot.
- The second thing I see some players do from this position is to drop the clubhead underneath the hands to try and stop the clubhead getting outside the correct swing plane. The problem is, in doing this, the clubface nearly always becomes open, and the ball will start to the right side of the target.
2) 
Some players who rotate their upper body too fast in the downswing are able to keep the club on the correct plane by dropping their arms behind their body, making their right arm very narrow.
This player might have the club on a good plane, but they will never be able to strike the ball with a solid shot. Their arms will be stuck behind their body until just before impact, with their right arm not able to straighten. As a result, they will create an impact position where they cannot compress the ball. They will just flip the ball into the air with no power. Or if they do straighten their right arm suddenly, just before impact, it will flip the clubface closed, resulting in big hooks.
All these faults are compensations of one fault, rotating the upper body too fast in the first part of the downswing.
The Fix: Do It Right
There is lots of information around with fixes of how to stop your upper body moving first in the downswing, but in my opinion, there is 1 move that if you understand and master, it will be almost impossible to move your upper body first. Look at the sequence of pictures I took from backswing to impact. What I what to show you is that from the top of the backswing, all the way to impact, my spine tilt away from the target is increasing. The middle of my hip, let’s say my belt buckle, is always moving towards the target and rotating, but the centre of my chest holds its position. This movement increases my spine tilt, making it impossible for my upper body to move too fast in the downswing.
Exercise
- Take your normal address position, placing a chair just outside of your left foot; a vertical line drawn up from the outside of your left foot should touch the chair. Place the ball on a tee.
- Make your backswing as normal.
- Now, practice moving your hips to the left to bump the chair, keeping your chest in the same position. There should also be a small amount of hip rotation as you move, and your left arm should have not gotten past parallel with the ground.
- Repeat this movement 3 times. It should feel like 3 pumps and then strike the ball with the same movement.
- Once you have a good feeling for the movement, you can hit some normal shots, repeating the same feel. You will never move your upper body too fast again!
