A normal foot pronates slightly during walking and running, meaning that the foot rolls inward. Pronation beyond normal, though, can cause problems all along your kinetic chain, commonly resulting in shin splints, achilles tendinitis, runner's knee and plantar fasciitis. Overpronation ranges from mild to severe. A gait analysis at a local running store or meeting with your podiatrist can help you determine the degree to which you pronate and what type of shoe is best for you.
How Many Pronators
According to Running Warehouse, most runners have some degree of overpronation. Between 50 percent and 60 percent of runners are considered mild pronators while 20 percent to 30 percent are severe overpronators. The rest of the population has a normal amount of pronation or tend to supinate, or allow their foot to roll out, as they run and walk.
Mild overpronation usually requires a stability shoe that provides some extra support in the arch to prevent you from rolling in too much. For moderate and severe overpronators, a motion-control shoe may be in order. These shoes have stiff heels and a dense material in a section of the midsole to keep the foot in a more desirable degree of alignment.