Foot types can be divided into three major groups: the flat foot (Pes Planus), the high arched foot (Pes Valgus) and the normal to low arched foot. A true 'flat foot' is very rare. In fact, less than 5% of the population have flat feet i.e. a foot with no arch present whatsoever and the entire bottom surface of the foot being flat on the ground. About 5-10% of people have a high arched foot. The majority of the population have a normal to low arch. Even though the arches appear to be normal most of us suffer from over-pronation during walking, running and standing, due to the hard, flat unnatural surfaces we walk on, combined with wearing unsupportive footwear. With every step we take the arches flatten and the ankles roll inwards. Pronation itself is not wrong because we need to pronate and supinate as part of our natural gait cycle. Pronation (rolling in) acts as a shock-absorbing mechanism and supination (rolling out) helps to propel our feet forward. Over-pronation occurs when the foot pronates too deep and for too long, not allowing the foot to 'recover' and supinate. Over-pronation hampers our natural walking pattern. It causes an imbalance and leads to wear and tear in several parts of the body with every step we take.
For those not familiar with the term pronation, you might be familiar with terms related to shoes and pronation such as ?motion control?, ?stability,? and ?neutral cushioned.? The terms motion control and stability are typically associated with the word ?over-pronation? or a foot that is supposedly pronating too much and needs correction. According to the running shoe industry, ?over-pronation? is a biomechanical affliction evident when the foot and or ankle rolls inward past the vertical line created by your leg when standing.
Overpronation can lead to injuries and pain in the foot, ankle, knee, or hip. Overpronation puts extra stress on all the bones in the feet. The repeated stress on the knees, shins, thighs, and pelvis puts additional stress on the muscles, tendons, and ligaments of the lower leg. This can put the knee, hip, and back out of alignment, and it can become very painful.
Pronounced wear on the instep side of shoe heels can indicate overpronation, however it's best to get an accurate assessment. Footbalance retailers offer a free foot analysis to check for overpronation and help you learn more about your feet.
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. 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.