Ground Reaction Force?

Traditional golf instruction often emphasizes the role of ground reaction forces in the golf swing. We've all heard the expression "the swing starts from the ground up" but is that what really happens? What actually starts the downswing?

The combination of modern high speed video and 3D motion capture (e.g., the K-Vest system) allows us to answer the question in ways that are difficult if not impossible to see with our eyes in real time. Modern kinematic analysis shows the greatest power comes from initiating the downswing by moving the hips and pelvis before any other parts of the body.

It's easiest to capture this movement on video from a face-on frontal view of the golfer. What we are looking for is the start of the movement pattern that eventually becomes the downswing. And we want to look at the best players on pro tours to learn what they do to generate power. 

A close look at the transition from backswing to downswing shows the first body segments to move towards the target are the hips and pelvis. Some players bump their hips laterally while others have a distinct rotational motion of the hips. But the greatest power with reasonable accuracy comes from initiating the downswing with hips/pelvis movement.

Most good players will then create some version of a downward movement of the central core of their body that effectively pushes their lower body against the ground. Since the ground isn't moving, the lower body reacts to the ground and the reaction energy is transferred upwards to help generate power for the swing.

Any careful analysis will lead to the same conclusion. The most powerful swing does not start from the ground up, it starts with a movement of the hips and pelvis. That's what the best players in the world have learned to do to generate power in the golf swing. 

We think understanding what starts the downswing is a critical concept because it influences the way you learn -- and are taught -- to swing a club. And it translates directly into power and distance and accuracy.