Clarification of hip movement during the squat

[pieza kake]

I used to squat fairly upright and now try to transition to a SS squat. My understanding is that during the eccentric phase the hips must be actively shoved back and not just down. However, during the concentric phase, hip movement is not the eccentric in reverse, i.e. the hips do not move forward, but upwards instead. Is this correct?

[Mark Rippetoe]

Correct.