Design patents protect the ornamental appearance of functional objects. So a design patent could protect the ornamental appearance of a shoe sole, which is obviously functional. However, if the appearance of the shoe sole is dictated primarily by functional considerations, in other words if it is shaped the way it is not merely for aesthetics, but because the shape improves one’s posture, then that appearance cannot be protected by a design patent. The appearance is then considered functional and not ornamental. It still might be possible to get a design patent on an aesthetic pattern used on the surface of the shoe sole, but not on the shape of the sole itself.

If this question relates to a real life issue for you and is not purely hypothetical, I very much encourage you to speak to your attorney. This site is for informational purposes only and should not be relied on as legal advice, which it is not. I am only explaining the general meaning of the laws and not their applicability to any specific factual circumstances. For example, the question of whether the appearance of an object is dictated primarily by functional considerations is a factual one that should be determined on a case-by-case basis.