Plummer and Bennett, the originators of the S&T, demonstrate in their instruction video a forward tilt of the spine angle toward the target during the upswing. With only 55% of of the weight on the front foot at address, the shoulders at address are almost even and the spine is upright and centered over the ball. On the backswing the weight shifts forward to about 60% and this gives a slight forward tilt to the spine. They emphasize that this tilt should not be exaggerated by dipping the shoulders too much. The downswing/finish produces a slight backward tilt of the spine away from the target which is produced when the hips are thrust forward.