Mike Granato and Shaun Webb from Athletic Motion Golf test the common advice of keeping the trail hip back during the downswing using 3D Gears motion data. By comparing restricted pelvic motion to Rory McIlroy's biomechanics, they show that holding the trail hip back limits pelvic rotation and ruins spine angle. They outline how the trail hip must move forward in the downswing using a knee-swap feel.
Holding your trail hip back restricts pelvic rotation (dropping to ~27°) and causes severe spine angle tilt and early extension.
Rory McIlroy's 3D data shows his trail hip moves 3 inches back in the backswing and 2 inches forward by impact.
Golfers should rotate around the center of their pelvis rather than 'wrench pivoting' on either hip.
Use the knee-swap feel in transition—where the trail knee flexes while the lead knee straightens—to allow natural forward hip movement.
Go deeper
Wild swings — Causes, drills and coaches for this miss