Where do you want to load your foot in relation to your center of mass ?

Screen Shot 2018-11-16 at 6.00.30 PM.png

Who do you want to be ? The guy loading his head over his foot
(narrow step width), or the gal loading the head and COM inside the foot (less narrow step width) ?
It is not hard to guess who is gonna be faster and more powerful from these photos. The lady is stacking the knee over the foot, the hip over the knee and stabilizing the hip and pelvis sufficiently and durably to keep the pelvis level for the next powerful loading step, and the other is flexion collapsing into the stance phase knee, insufficiently loading the hip and thus dropping the opposite side pelvis. He is not stacking the joints, there is a pending cross over (look at the swing leg knee approaching midline with barely any knee spacing, thus guaranteeing a cross over step or at the very least a very narrow step width.)
Sure, some one is going to say one is a distance runner and the other is a sprinter. Yes, and our point is that the sprinter is not head-over-foot, the one with all the highly suspect flaws is head over foot ! Wider step width means more glutes. Go ahead, walk around right now with a very narrow step width and see how little efficient glute contraction you get, then walk with a notably wider step width, and you will see wider means more glutes. Keep your COM moving forward, not oscillating back and forth sideways over each stance foot, that is a power leak.

Screen Shot 2018-11-16 at 6.00.11 PM.png

The distance runner is showing sloppy in technique. Say what you want, but one of these runners is weak and very likely at greater risk for injury, the other is strong and durable, and likely at less risk for injury.
If you ask us, but what do we know . . . .
So, again, was ask . . . . which one do you want to be ?