Pronation or eversion is the inward roll of the foot while walking or running. Another way to look at pronation instead in terms of the degree of inward roll is in terms of where the foot pushes off at the end of each step, or at the end of the gait cycle. There are three main types of pronation in human gait: neutral pronation, overpronation, and underpronation or supination. While both overpronation and supination occur while walking and standing, they are usually more pronounced and the effects amplified while running. Those who overpronate tend to push off almost completely from the big toe and second toe. As a result, the shock from the foot?s impact doesn?t spread evenly throughout the foot and the ankle has trouble stabilizing the rest of the body. Additionally, an unnatural angle forms between the foot and ankle and the foot splays out abnormally. It is common even for people who pronate normally to have some angle between the foot and the ankle, but not to the extent seen in those who overpronate. In normal pronation the weight distributes evenly throughout the foot.
Although there are many factors that can contribute to the development of these conditions, improper biomechanics of the body plays a large and detrimental role in the process. Of the many biomechanical elements involved, foot and ankle function perhaps contribute the most to these aches and pains.
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.
Look at the wear on your shoes and especially running trainers; if you overpronate it's likely the inside of your shoe will be worn down (or seem crushed if they're soft shoes) from the extra strain.
Non Surgical Treatment
Studies have shown that the most effective way to dexrease a high Q angle and lower the biomechanical stresses on the knee joint is to prevent excessive pronation with custom-maflexible orthotics. One study found that using soft corrective orthotics was more effective in reduknee pain than a traditional exercise program. A more recent study showed that Q angle asymmetries, secondary to excessive pronation affecting knee alignment, can be effectivecontrolled or corrected utilizing custom-made, flexible orthotics. Another project involving meof a running club determined that 75% of those using orthotics eliminated or greatly reduced pain in the feet, ankles, shins, knees and hips
Subtalar Arthroereisis. The ankle and hindfoot bones/midfoot bones around the joint are fused, locking the bones in place and preventing all joint motion. This may also be done in combination with fusion at other joints. This is a very aggressive option usually reserved for extreme cases where no joint flexibility is present and/or the patient has severe arthritic changes in the joint.