The foot and knee action Jack has there requires more axis tilt/hip tilt, putting a lot of strain on the left knee, hip and lower back and resulting in a reverse 'c' style finish position. Useful for hitting high fades and very difficult to draw the ball from.
EdZ,
I know you are an avid student of the game and are more than a little familiar with the work of Alex Morrison. Could you trace the Morrison-Picard-Grout-Nicklaus geneology of this exaggerated 'Ankle Roll' move?