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.
Overpronation often occurs in people with flat feet, whose plantar fascia ligament is too flexible or too long, and therefore unable to properly support the longitudinal arch of the foot. People tend to inherit the foot structure that leads to overpronation. In a normal foot the bones are arranged so that two arches are formed, the longitudinal and the transverse. Ligaments hold all the bones in their correct positions, and tendons attach muscles to bones. If the bones are held together too loosely, they will tend to move inwards as this is the easiest direction for them to go. Over time the soft tissue structures will adjust to the misalignment and the foot will become permanently over-flexible, with a flat arch.
Due to the laxity of the soft tissue structures of the foot, and the fact that the joints are not held together properly, the bones of the feet shift. When this occurs, the muscles that attach to these bones must also shift, or twist, in order to attach to these bones. The strongest and most important muscles that attach to our foot bones come from our lower leg. So, as these muscles course down the leg and across the ankle, they must twist to maintain their proper attachments in the foot. This twisting of these muscles will cause shin splints, Achilles Tendonitis, generalized tendonitis, fatigue, muscle aches and pains, cramps, ankle sprains, and loss of muscular efficiency (reducing walking and running speed and endurance). The problems we see in the feet, which are due to over-pronation include bunions, heel spurs, plantar fasciitis, fallen and painful arches, hammertoes, metatarsalgia (ball of foot pain), and calluses.
When sitting, an over-pronating foot appears quite normal, i.e. showing a normal arch with room under the underside of the foot. The moment you get up and put weight on your feet the situation changes: the arches lower and the ankle slightly turns inwards. When you walk or run more weight is placed on the feet compared to standing and over-pronation will become more evident. When walking barefoot on tiles or timber floors over-pronation is more visible, compared to walking on carpet or grass.
Non Surgical Treatment
Heel counters that make the heel of the shoe stronger to help resist/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.
Strengthen the glutes to slow down the force of the foot moving too far inward. Most individuals who over-pronate have weak glute muscles and strengthening this area is a must. A simple exercise to strengthen glutes is lateral tube walking across a field/court/room. Place a lateral stretch band around your ankles and move your leg sideways while keeping your feet forward.