Platform

A platform thickens the sole under the front of the foot, so both ends of the shoe rise instead of just the back. Anything of about half an inch or more under the toe counts; below that, the sole is simply thick. The construction shows up two ways: as a visible slab, or concealed inside the shoe beneath the insole. Listings call the concealed version a hidden platform, and the shoe passes for an ordinary pump from the outside.

One subtraction tells you how the shoe will feel. Take the heel height, remove the platform depth, and you have the pitch, the angle your foot actually stands at. A 5" heel on a 1.5" platform gives a 3.5" pitch, which most people can walk in. The same 5" heel with no platform is a seated-occasion shoe for most feet. Once a platform enters the picture, the listed heel height on its own tells you almost nothing.

The cost is flexibility and ground feel. A thick forefoot cannot bend, so your step changes from a roll to a flat-footed plant. Stairs need more attention because the sole hides the edge from your foot. Weight climbs too: an inch of added sole is an inch of material you lift with every stride.