Anatomically speaking, foot pain always seems to affect the very distal part of the lower limb. A pain in the foot is quite literal, unlike a pain in the ass, which is more of an expression. Interestingly, a pain in the foot can be quite a pain in the ass, which appears quite impossible in a literal sense, at least on the same person. However, a scenario could be that an attacking person kicks someone in the rear, and in doing so injures both his foot ("My foot!") and the victim's behind ("My ass!"). In this case, the best way to avoid foot pain is not by seeking a podiatrist but enrolling in anger management.
To Cure That Insatiable Need to Read More on Feet