Why Pelvis Movement on 3D Doesn’t Always Indicate Sway

A 3D motion capture graph can show the center of a golfer’s pelvis moving away from the target during the backswing, but doesn’t necessarily mean the golfer is swaying.

As Dr. Greg Rose demonstrates, the pelvis is shaped more like an ellipse than a circle. When a golfer rotates around a relatively stable trail hip, the center of the pelvis can move away from the target without a comparable lateral shift of the trail hip.

In the example from our lab, the pelvis center travels nearly three inches, while the trail hip and knee move only about half an inch before remaining relatively stable through the turn. Looking at the pelvis center alone could lead a coach to misinterpret that movement as excessive sway.

That’s why we look at both. Before deciding what a golfer needs to change, we need to understand exactly what we’re measuring.

If you're interested in learning more about in-depth golf kinematics, check out our Advanced 3D course. It's not a Certification course so there is no Level 1 prerequisite, but it's the most thorough explanation to how we analyze and interpret 3D data.