Create secondary tilt from a hip bump, not a spine tilt
The coach describes the reverse K (what he calls secondary tilt) for a right-handed player with a post brace. He explains it is not really a function of tilting the spine back; because the pelvis and belt line sit perpendicular to the spine, a small hip bump produces the tilt. He adds that the extra tilt look is optics from the trail hand reaching lower for the club, which lowers the shoulder. Secondary tilt lets you turn to the inside of the back foot.
Channel: PorzakGolf
Watch official source at 3:53