Pes planus is the medical term for flat feet. It comes from Latin, Pes = foot and Planus = plain, level ground. Very few people suffer from this condition, as a true flat foot is very rare. Less than 5% of the population has flat feet. The majority of the population, however, has fallen arches (an estimated 60-70% of the population) known in the medical profession as ?excess pronation? or over-pronation. Over-pronation means the foot and ankle tend to roll inwards and the arch collapses with weight-bearing. This is a quite a destructive position for the foot to function in and may cause a wide variety of foot, leg and lower back conditions.
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.
Bunions, calluses and crooked toes may indicate alignment problems. So, it is important to ascertain the condition of a client's toes. Check the big toe to determine if the first joint of the toe is swollen, has a callus or bunion, and/or looks as though it abducts (i.e., hallux valgus) rather than pointing straight ahead. Also, look to see if the lesser toes seem to "curl up" (i.e., the person has hammer or claw toes). This may be indicative of damage to, or inflexibility of the plantar fascia caused by excessive flattening of the foot.
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.
With every step we take, we place at least half of our body weight on each foot (as we walk faster, or run, we can exert more than twice our body weight on each foot). As this amount of weight is applied to each foot there is a significant shock passed on to our body. Custom-made orthotics will absorb some of this shock, helping to protect our feet, ankles, knees, hips, and lower back.