FWIW female hips are wider than male hips for a given height and weight. So at rest their thighs are angled more directly inward than a male. It is this that causes the "swaying."
Given any sort of high heel, it is frankly dangerous to walk by planting the heel first, it will end you up on the floor until you get over that technique. By planting the shoe on the floor both ends at the same time (flat) it will produce the sway and it is easy to maintain it when you're not in heels by using the same motion.
btw my wife is a perpetual heel striker, I hear her pounding the floor with her heels all the time. She doesn't even own a pair of high heels and would not know how to walk in them if she did.
