The Facts Regarding Overpronation Of The Feet

posted on 03 Jun 2015 13:30 by farmersllqfshgjj
Overview

Pronation is a turning outward of the foot at the ankle, which allows the foot to flatten. The pronation helps to absorb some of the compressive shock forces, torque conversion, adjustment to uneven ground contours, and maintenance of balance. It is necessary to have a certain amount of pronation to disseminate the energy of the foot-strike. If there is too little or too much pronation injuries may occur. When a foot and ankle pronates to a great degree, we call it over-pronation. Normally you can see the Achilles Tendon run straight down the leg into the heel. If the foot is over-pronated, the tendon will run straight down the leg, but when it lies on the heel it will twist outward. This makes the inner ankle bone much more prominent than the outer ankle bone.Overpronation

Causes

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.

Symptoms

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.

Diagnosis

Firstly, look at your feet in standing, have you got a clear arch on the inside of the foot? If there is not an arch and the innermost part of the sole touches the floor, then your feet are over-pronated. Secondly, look at your running shoes. If they are worn on the inside of the sole in particular, then pronation may be a problem for you. Thirdly, try the wet foot test. Wet your feet and walk along a section of paving and look at the footprints you leave. A normal foot will leave a print of the heel, connected to the forefoot by a strip approximately half the width of the foot on the outside of the sole. If you?re feet are pronated there may be little distinction between the rear and forefoot, shown opposite. The best way to determine if you over pronate is to visit a podiatrist or similar who can do a full gait analysis on a treadmill or using forceplates measuring exactly the forces and angles of the foot whilst running. It is not only the amount of over pronation which is important but the timing of it during the gait cycle as well that needs to be assessed.Foot Pronation

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.

Surgical Treatment

Calcaneal "Slide" (Sliding Calcaneal Osteotomy) A wedge is cut into the heel bone (calcaneus) and a fixation device (screws, plate) is used to hold the bone in its new position. This is an aggressive option with a prolonged period of non-weightbearing, long recovery times and many potential complications. However, it can and has provided for successful patient outcomes.