Whether you agree the hips and legs are body parts or not....at least you're very close in what parts have "dragster" parts in them that needs to slam the "brakes" on into contact, so other parts can fly by them.
if you ever get to get a look at a kmotion graph. You will see the hips move the slowest during the sequence and are more of a stabilizer than a generator. Fast hips are poison in any rotary or cross body action.