MUD Mired in time...

The distance from center of mass to each hip center is just about equal to the ankle to forefoot roll over length. This means that both share this ground adaptive allowance. If you waste one of these? High heels... Wearing high heels requires more up & down fanny motion about the center of mass to offset the ankle arc loss (to fashion). Lumbar spinal fusion to the pelvis kills this pelvic tilt contribution and makes wearing high heels, or anything that constrains ankle movement, quite uncomfortable and exhausting.

Are there alternates to Inman’s determinants? Yes, a big one. A very large radius single wheel using a smaller arc that is centered vertically also mimics this and (an alternative discussed in our ebooks that follow). Inman did not include this nor what happens when neurology is amiss (not from missing anatomy).