Pronation is a normal motion that our feet make as they walk. With each step, the heel touches the ground first, then the foot rolls forward to the toes, causing the ankle to roll inward slightly and the arch to flatten out. That?s normal. But when that rolling inward becomes more pronounced, that?s over-pronation, which is a big problem. You can usually see over-pronation by looking at the back of the leg and foot. The Achilles tendon normally runs straight down from the leg to the foot, hitting the floor at a perpendicular angle. In feet that over-pronate, the Achilles tendon will be at a slight angle to the ground and the ankle bone will appear more prominent than usual.
Overpronation often occurs in people with flat feet, whose plantar fascia ligament is too flexible or too long, and therefore unable to properly support the longitudinal arch of the foot. People tend to inherit the foot structure that leads to overpronation. In a normal foot the bones are arranged so that two arches are formed, the longitudinal and the transverse. Ligaments hold all the bones in their correct positions, and tendons attach muscles to bones. If the bones are held together too loosely, they will tend to move inwards as this is the easiest direction for them to go. Over time the soft tissue structures will adjust to the misalignment and the foot will become permanently over-flexible, with a flat arch.
Because pronation is a twisting of the foot, all of the muscles and tendons which run from the leg and ankle into the foot will be twisted. In over-pronation, resulting laxity of the soft tissue structures of the foot and loosened joints cause the bones of the feet shift. When this occurs, the muscles which attach to these bones must also shift, or twist, in order to attach to these bones. The strongest and most important muscles that attach to our foot bones come from our lower leg. So, as these muscles course down the leg and across the ankle, they must twist to maintain their proper attachments in the foot. Injuries due to poor biomechanics and twisting of these muscles due to over-pronation include: shin splints, Achilles Tendonitis, generalized tendonitis, fatigue, muscle aches and pains, cramps, ankle sprains, and loss of muscular efficiency (reducing walking and running speed and endurance). Foot problems due to over-pronation include: bunions, heel spurs, plantar fasciitis, fallen and painful arches, hammer toes, and calluses.
The best way to discover whether you have a normal gait, or if you overpronate, is to visit a specialty run shop, an exercise physiologist, a podiatrist or a physical therapist who specializes in working with athletes. A professional can analyze your gait, by watching you either walk or run, preferably on a treadmill. Some facilities can videotape your gait, then analyze the movement of your feet in slow-motion. Another (and less costly) way is to look at the bottom of an older pair of run shoes. Check the wear pattern. A person with a normal gait will generally see wear evenly across the heel and front of the shoe. A person who overpronates will likely see more wear on the OUTside of the heel and more wear on the INside of the forefoot (at the ball). A person who supinates will see wear all along the outer edges of the shoe. You can also learn about your gait by looking at your arches. Look at the shape your wet feet leave on a piece of paper or a flat walking surface.
Non Surgical Treatment
Supportive orthotics in the shoe is a method commonly implemented to treat many common running injuries associated with pronation. An advantage of orthotics is that they often allow the sufferer to continue to participate in athletic activity and avoid other treatment options that could be potentially costly and time consuming. Seventy-five percent of injured runners are successfully treated with the prescription of orthoses. Orthotics are the most effective treatment for symptoms that develop from unusual biomechanics within the body such as overpronation, resulting in either great improvement or complete healing of the injury in about half the cases.
Subtalar Arthroereisis. Primary benefit is that yje surgery is minimally invasive and fully reversible. the primary risk is a high chance of device displacement, generally not tolerated in adults.
An implant is pushed into the foot to block the excessive motion of the ankle bone. Generally only used in pediatric patients and in combination with other procedures, such as tendon lengthening. Reported removal rates vary from 38% - 100%, depending on manufacturer.