Flat arches: If you have flat arches, your feet tend to overpronate, so you need stability or motion control shoes, says Rebekah Broe, the senior director of product performance for Hoka.

If left untreated, fallen arches can cause arthritis and back pain. Here, experts reveal how to ease pain from flat feet at home — and when to see a doctor.

Nearly 1.5 billion people around the globe (including Elvis Costello and Elton John) suffer from flat feet, a condition in which the arch of the foot is virtually non-existent.