[BerntR]

I basically agree with DG, but Hip Action does have a direct influence on the shoulder turn. Whether it is an area that needs attention depends on how well it works and how automatic it has become:

10-15 Hip action

10-15-A: Standard
The Hips initiate and lead throughout - pulling the Shoulders in both directions

10-15-B: Delayed
/..../ The hips then take over and lead and power the Downstroke Shoulder turn /....../

Then of course you have Short and Zero (C & D) that doesn't lead the shoulder turn in the down stroke but they are hardly relevant in full motion.