Probably at that time they were teaching something very close to S&T (their own swing looks similar today but they say they teach more diverse patterns).
I think that what mostly keeps the head steady is the left tilt (thoracic bend) and the extension of the back. In S&T the straitening of the rear leg is more to keep the hips turning. In addition, the slant of the hips releaves lower back pressure.
Hybrid Mode
