[Jeff]

RJW

I think that you are right. If one starts the downswing with pelvis shift-rotation movement, that lower body action moves the lumbar spine left-laterally and increases the degree of secondary axis tilt. Then, when the upper torso subsequently rotates perpendicularly around the spinal tilt (which has increased), the right shoulder can move downplane. A golfer who starts the torso rotation with an upper torso turn (without a preceding lower body shift-rotation movement) can only turn the shoulders more horizontally which predisposes to an OTT move.

Jeff.