Runners often lament about recurring injuries that seem to resist stretching, rest, and extra attention. Many runners are actually causing their own injuries as a result of using the wrong shoes for their running gait.
Not all runners have the same gait, and using the wrong shoe for the wrong type of gait can increase injury risks and exacerbate existing pains. By understanding pronation and how to choose shoes according to pronation, a runner can drastically reduce the risk of injury.
What is Pronation?
"Pronation" is how the foot turns when it hits the ground. A runner's feet will pronate in one of three ways: normal pronation, over-pronation, and under-pronation. Under-pronation is more commonly referred to as "supination." Normal pronation occurs when the runner's foot hits the ground with the heel first, and then rotates 15% toward the inside of the foot. Under- and over-pronation occur when the foot rolls to the inside at an angle less than or greater than this angle.
Over-Pronation
If the outside of a runner's heel hits the ground first, but then the foot rolls inward more than 15%, then that runner is said to have an over-pronated gait. When this happens, the big toe and the second toe bear the burden of propelling the runner forward. Runners with this uneven, unbalanced gait are usually very unstable.
Determining Over-Pronation: If the bottom of a runner's shoe reveals excessive wear around the foot ball, the big toe, and the inside of the heel, then that runner likely has an over-pronating gait.
Injury Risks of Untreated Over-Pronation: Runners that over-pronate do not effectively distribute the shock that occurs when the foot hits the ground. The over-exaggerated rotation of the foot also causes increased strain on the runner's foot, shin, and knee. The most common injuries that result from uncorrected over-pronation are shin splints, plantar fasciitis, and patellofemoral pain syndrome (more commonly known as the dreaded "runner's knee").
Best Shoes for Runners That Over-Pronate: When choosing a running shoe, an over-pronating runner should select models that offer a lot of support and cushioning to lessen the effects of shock and limit foot rotation.
Under-Pronation
A runner that under-pronates (or supinates) will land on the outside heel, but unlike runners that over-pronate, the foot will rotate inward at an angle less than 15%. As a result, it is the outside of the foot, including the pinkie toe, that must propel the runner forward.
Determining Supination: If a runner's shoe shows excessive wear on the outside, then that runner probably supinates.
Injury Risks of Untreated Supination: A runner that supinates will excessively strain the calves, illiotibial band, hamstrings, and even muscle groups higher up in the body, like shoulders and neck. These runners are more susceptible to plantar fasciitis, heel spurs, and ankle sprains.
Best Shoes for Runners That Supinate: Runners that supinate should avoid shoes that provide excessive support or limit range of foot movement. Instead, runners can minimize the injury risks associated with under-pronation by selecting shoes that are cushioned but still flexible, and might even benefit from an added insole. Consult with professionals, such as those from Adult & Pediatric Orthopedics SC, with further questions.
