Shannon SteelSlave wrote:I think a half an inch can make a difference. I can walk fine on 6 inch, but 6.5, elephant with the legs of a crane on an escalator. I have heard from another member here that 4 - 5 inch is a sort of "comfort cut off" where the geometry of the incline starts to take its toll.
It makes a huge difference. At 6 inches (depending on how big your feet are), adding any height doesn't lift your ankle, it just pitches your foot (and shin, if you've reached the limit of your ankle's flexibility) forward.
Consider: if your foot is 10" long, the distance between the pivot points of your ankle joint and the ball of your big toe is only about 6". A 6" heel is pushing that line basically vertical, and any extra height pushing on the back of the heel is pushing your ankle joint over the top of the toe joint.
Note that the ankle joint is above and forward of the heel, so you actually reach the point that extra heel height is not translating into extra ankle/overall height around the 4-5" heel rise range, so if you want to be taller than what a 4" or so heel can do for you, you need to be looking at platforms (or ballet heels) that lift the whole foot off the floor.
Obviously, those numbers depend on foot size - larger feet can take higher heels before running out of lift, but then they're typically carrying a larger body too ...