- The dancer in this photo is giving us an exaggerated version of overpronation. Looks dramatic onstage, but painful as a daily wear-pattern!
One of the key words in my practice is “pronation”. This refers to the motion of the foot, and how much the feet roll during walking and running. A roll-factor of about 15% inward (where the toes point slightly toward each other as part of your gait) is ideal. This slight inward angle during movement is critical to proper shock absorption, and prevents your feet from getting injured. Impact sports and weight gain make this percentage even more important.
Your degree of pronation also defines how various bones, muscles, ligaments and tendons move and work. Extremes in pronation—overpronation, underpronation—can result in painful inflammation and other injuries over time.
HERE’S THE RUN-DOWN:
NORMAL PRONATION, where the feet roll inward about 15% — The outside of the heel makes initial contact when you walk and run. As you move forward, the foot comes into complete contact with the ground and can support your body weight with no problem. The slight roll of the foot optimally distributes impact. At the end of each step or get cycle, you push off evenly from the front of the foot.
OVERPRONATION is similar to the above, except that the foot rolls inward more than the ideal 15%. This means that your foot and ankle have problems stabilizing the body, and so shock isn’t absorbed as efficiently. People who overpronate “push off” with their big toe and second toe, and this places extreme force on these two toes.
People who are born with “flat” feet overpronate naturally. Overpronation, over the years, further flattens out the foot, collapsing the arch. This can lead to painful Plantar Fasciitis.
UNDERPRONATION, or supination, is less common than overpronation. Instead of rolling their feet too far inward at impact, underpronators don’t roll in enough. Like overpronators, they do not roll their feet inward within the ideal 15% range. Instead, they rotate their foot away from the center of the body. Think of the famous “duck walk” of Charlie Chaplin, where he walks with his toes pointed away from his body and his heels almost touching—similar to a ballet dancer’s “turnout”.
Underpronating in real life prevents feet from absorbing impact while walking and running, and may lead to joint inflammation and muscle injuries. This is because the forces of impact are concentrated on a small area along the outside of the foot, and so the foot cannot distribute the shock evenly. In underpronation, the “push off” phase places tremendous pressure on the “baby” toe and smaller toe, causing stress on these joints.
HOW TO CHECK?
Get out an old pair of shoes, preferably running shoes. Shoes that you’ve worn a lot. Set them on an even, straight table surface and get eye-level with the soles on the tabletop. If you have perfect feet, gold star, the soles of the shoes will rest pretty much in a flat line on the surface of the table. A slight—SLIGHT—rock inward is normal and okay.
But if those shoes are rockin’, as in tipping over, it’s time to go a-knockin’ on the door of a podiatrist. Extreme wear on the soles of shoes is like “scalloping” or uneven wear on the tires of your car: it indicates an uneven distribution of weight. The good news: pronation issues often may be addressed with our over-the-counter orthotics, DoctorInsole™.