Pronation is the natural way that our feet absorb shock: when our feet strike the ground the arches flex down and in to disperse the impact. Everyone pronates! Contrary to popular misconception it is healthy and normal. The problem begins when one or both of our feet pronate too much. When the arches flex too far inward or stay collapsed for too long pronation is considered excessive. We call this overpronation. The amount of overpronation can vary from mild to severe. In severe overpronation the feet and ankles can rotate too far inward just during standing.
Pronation can occur as an overuse syndrome in active runners, where a great deal of stress is placed on ligaments and tendons that support the medial column. Obesity is another predictor for pronation and deterioration of the medial ligaments and posterior tibial tendon due to excessive stress on these tissues. Acute Trauma can also lead to over-pronation when ligaments are torn or tendon is ruptured. Once again this can lead to a collapse of the medial column. Arthritic conditions involving the knee joint when the joint is in varus (inner collapse) posture, this places the center of gravity over the ankle joint rather than the foot causing undue pressure on the inner ankle.
Because overpronation affects the entire lower leg, many injuries and conditions may develop and eventually cause problems not only in the leg and foot, but also the knee, hips and lower back. Pain often begins in the arch of the foot or the ankle. Blisters may develop on the instep, or on the inside edge of the heels. As overpronation continues and problems develop, pain will be felt elsewhere, depending on the injury.
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
Adequate footwear can often help with conditions related to flat feet and high arches. Certified Pedorthists recommend selecting shoes featuring heel counters that make the heel of the shoe stronger to help resist or reduce excessive rearfoot motions. The heel counter is the hard piece in the back of the shoe that controls the foot?s motion from side-to-side. You can quickly test the effectiveness of a shoe?s heel counter by placing the shoe in the palm of your hand and putting your thumb in the mid-portion of the heel, trying to bend the back of the shoe. A heel counter that does not bend very much will provide superior motion control. Appropriate midsole density, the firmer the density, the more it will resist motion (important for a foot that overpronates or is pes planus), and the softer the density, the more it will shock absorb (important for a cavus foot with poor shock absorption) Wide base of support through the midfoot, to provide more support under a foot that is overpronated or the middle of the foot is collapsed inward.
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.