Hip Rotation

Should you push your hips to rotate?
A. Before front foot strike
B. halfway into front foot strike
C. After front foot strike
Im not really sure which one is right

The hips should open into foot plant if you want to achieve separation (which you are). It should be the back hip being dominant though in opening the hip. Baseballthinktank has some good videos on this. Some guys to look at would be Aroldis Chapman and Lance Mccullers.