Pronation refers to the amount of inward roll that occurs in your foot as it strikes the ground. As a runner, you may have an ideal level of pronation, you may overpronate or you may underpronate, also known as supination. An ideal degree of pronation involves a very slight movement of your ankle bone inward as your foot impacts the ground. Overpronation involves too much inward rolling movement; supination involves an outward rolling motion. Depending which you have, there are measures you can take to correct the problem while running.
Determine whether you overpronate or underpronate, or whether you have neutral pronation. You can perform a simple test at home to work this out. Barefoot, step into some water and then step firmly onto a brown paper bag laid on the floor. The aim is to stamp your wet footprint onto the bag.
Look at your wet footprint on the bag. If the area where the arch of your foot pressed on the bag is visibly wet, you have overpronation. If your wet footprint has little or no arch area, you have supination. Among the general population, and among runners, supination is less common than overpronation.
Purchase a pair of running shoe designed for the kind of pronation you have. Mild overpronation is typically corrected with supportive running shoes. Severe overpronation may require motion-control shoes that force your foot to follow a more neutral path. Runners with supination typically benefit from neutral shoes.
When running in the shoes you have chosen as most appropriate for your type and degree of pronation, pay attention to the position of your feet during each striking action. Assess whether you are pronating, and aim to correct your foot position if necessary.