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.
Generally fallen arches are a condition inherited from one or both parents. In addition, age, obesity, and pregnancy cause our arches to collapse. Being in a job that requires long hours of standing and/or walking (e.g. teaching, retail, hospitality, building etc) contributes to this condition, especially when standing on hard surfaces like concrete floors. Last, but not least unsupportive footwear makes our feet roll in more than they should.
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.
You can test for pronation by looking at the leg and foot from the back. Normally you can see the Achilles Tendon run straight down the leg into the heel. If the foot is 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.
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.