It is estimated that around 80% of the population suffer from excessive pronation. This condition is common in all types of people from children to the elderly and from top athletes to people with a sedentary lifestyle. The feet become misaligned and combined with poor posture roll inwards to gain ground contact, the arches become flattened producing the condition known as excessive pronation. When the feet are excessively pronated a combination of poor posture and diminished shock absorption results in some areas of the feet being subjected to excessive stress and pressure. This can lead to various conditions including knee and back problems, as well as foot problems and deformities.
Flat feet don't automatically mean you have a problem. The problem can be divided into a flexible flat foot or rigid flat foot. The rigid flat foot is one that does not change shape when the foot becomes weight bearing. i.e. it does not go through the excessive motion of pronation. Generally speaking this foot does not provide too many problems. The flexible flat foot is the type that when it becomes weight bearing the foot and ankle tends to roll in (pronates) too far. This type of person will often say I have great arches but when I stand up much of this arch disappears as the foot excessively pronates When the foot is excessively pronating and causing problems like sore ankles, feet or knees when standing or exercising then arch support is extremely important to restore the foot structure.
Overpronation can be a contributing factor in other lower extremity disorders, such as foot pain, plantar fasciitis, ankle injuries, medial tibial stress syndrome (shin splints), periostitis, stress fractures and myofascial trigger points. Overpronation increases the degree of internal tibial rotation, thereby contributing to various knee disorders such as meniscal injury or ligament sprains. The effects of the postural deviation are exaggerated in athletes due to the increase in foot strikes while running and the greater impact load experienced. When running, three to four times the body weight is experienced with each foot strike.2 If overpronation exists, the shock force is not adequately absorbed by the foot and is transmitted further up the kinetic chain.
One of the easiest ways to determine if you overpronate is to look at the bottom of your shoes. Overpronation causes disproportionate wear on the inner side of the shoe. Another way to tell if you might overpronate is to have someone look at the back of your legs and feet, while you are standing. The Achilles tendon runs from the calf muscle to the heel bone, and is visible at the back of the ankle. Normally it runs in a straight line down to the heel. An indication of overpronation is if the tendon is angled to the outside of the foot, and the bone on the inner ankle appears to be more prominent than the outer anklebone. There might also be a bulge visible on the inside of the foot when standing normally. A third home diagnostic test is called the ?wet test?. Wet your foot and stand on a surface that will show an imprint, such as construction paper, or a sidewalk. You overpronate if the imprint shows a complete impression of your foot (as opposed to there being a space where your arch did not touch the ground).
Non Surgical Treatment
Not all over pronation is treated. Although, when it appears to be a causitive factor that is contributing to pain,or development of structural deformities, there are various degrees of treatment.In some cases specific shoes may be all that is required. In other cases, paddings or strapping, are prescribed and where necessary orthotic therapy. A podiatric assesment would be advised to asses this.
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.