Running attracts many athletes because it requires little gear and few skills to get started. As you spend more time in the sport, you realize that technique, such as form and breathing, impacts performance. Similarly, improper technique and biomechanics can hurt performance. Supination is one biomechanical problem that not only affects your gait, but can lead to injury.
Supination is the outward roll of the foot during your running stride. It is the opposite of pronation, which causes an inward roll of the foot. As your foot hits the ground during supination, your heal strikes first and your weight rolls to the outside of your foot.
Pushing off the outside of your foot during supination lessens your foot's ability to absorb the impact of your stride. This results in possible heel, knee, hip and back pain. Common running injuries resulting from supination include plantar fasciitis, shin splints and ankle sprains.
Runners with high arches are more prone to supination as the lack of arch support pushes the weight of the stride to the outside of the foot. You can check to see if your have high arches by walking across concrete with wet feet. A high-arch footprint will show your toes, heel and just a thin strip of the outside of your foot. You will not see the majority of your sole.
A specialist, such as a podiatrist, can analyze your gait to check for supination. If you suspect supination, check the soles of your running shoes. If you supinate, your shoes will wear down faster on the heel and outside of your shoe.
Orthotic inserts help correct supination by providing support that prevents the outward over-rotation of your foot. If you experience running injuries that you suspect are from supination, talk with a podiatrist about having orthotics made for your feet. While it's possible to purchase orthotics from a footwear store, a specially made pair from a doctor will better correct your specific biomechanical problems.
Shoes with extra padding provide cushion to absorb the impact from your heel strike. This can help prevent the overuse injuries associated with supination.
You may be able to correct your stride to stop over-supination. Changing your gait so your midsole strikes the ground first, instead of your heel, helps lessen the impact of your stride and prevents your foot from rolling outward. The outward roll during supination starts with your heel strike. Eliminating this first impact makes it more difficult for your foot to roll outward.