One of the most common causes of foot and leg discomfort is a condition known as overpronation. Normal pronation, or "turning inward" of the foot is necessary as the foot adapts to the ground. With over pronation, the arch flattens, collapses, and soft tissues stretch. This causes the joint surfaces to function at unnatural angles to each other. When this happens, joints that should be stable now become very loose and flexible. At first, over pronation may cause fatigue. As the problem gets worse, strain on the muscles, tendons, and ligaments of the foot and lower leg can cause permanent problems and deformities.
Unless there is a severe, acute injury, overpronation develops as a gradual biomechanical distortion. Several factors contribute to developing overpronation, including tibialis posterior weakness, ligament weakness, excess weight, pes planus (flat foot), genu valgum (knock knees), subtalar eversion, or other biomechanical distortions in the foot or ankle. Tibialis posterior weakness is one of the primary factors leading to overpronation. Pronation primarily is controlled by the architecture of the foot and eccentric activation of the tibialis posterior. If the tibialis posterior is weak, the muscle cannot adequately slow the natural pronation cycle.
It is important to note that pronation is not wrong or bad for you. In fact, our feet need to pronate and supinate to achieve proper gait. Pronation (rolling inwards) absorbs shock and supination (rolling outwards) propels our feet forward. It is our body?s natural shock-absorbing mechanism. The problem is over-pronation i.e. the pronation movement goes too deep and lasts for too long, which hinders the foot from recovering and supinating. With every step, excess pronation impedes your natural walking pattern, causing an imbalance in the body and consequent excessive wear and tear in joints, muscles and ligaments. Some common complaints associated with over-pronation include Heel Pain (Plantar Fasciitis) ,Ball of foot pain, Achilles Tendonitis, Shin splints, Knee Pain, Lower Back Pain.
The best way to discover whether you have a normal gait, or if you overpronate, is to visit a specialty run shop, an exercise physiologist, a podiatrist or a physical therapist who specializes in working with athletes. A professional can analyze your gait, by watching you either walk or run, preferably on a treadmill. Some facilities can videotape your gait, then analyze the movement of your feet in slow-motion. Another (and less costly) way is to look at the bottom of an older pair of run shoes. Check the wear pattern. A person with a normal gait will generally see wear evenly across the heel and front of the shoe. A person who overpronates will likely see more wear on the OUTside of the heel and more wear on the INside of the forefoot (at the ball). A person who supinates will see wear all along the outer edges of the shoe. You can also learn about your gait by looking at your arches. Look at the shape your wet feet leave on a piece of paper or a flat walking surface.
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.
The MBA implant is small titanium device that is inserted surgically into a small opening between the bones in the hind-mid foot: the talus (ankle bone) and the calcaneus (heel bone). The implant was developed to help restore the arch by acting as a mechanical block that prevents the foot from rolling-in (pronation). In the medical literature, the success rate for relief of pain is about 65-70%. Unfortunately, about 40% of people require surgical removal of the implant due to pain.