Normal, healthy feet pronate! Normal pronation does not need to be ?corrected?. However, some people OVER-pronate. Those people need a shoe that supports their over-pronating foot to help guide the foot and avoid injury. So, what does pronation mean exactly? Well, ?pronate? is the word used to describe the natural motion of the foot after it strikes the ground. When a person with a normally pronating foot runs, the outside part of the heel strikes the ground. As the individual shifts the body weight forward, the foot rolls inward (pronates) and the entire foot comes into contact with the ground. This allows the foot to properly support the body and absorb the impact forces. Motion continues forward and the peron pushes off (called ?toe off?) evenly from the front of the foot. Someone who OVER-pronates strikes the ground with the heel in the same way, but the foot rolls too far inward (overpronation). This causes foot and ankle strain, as it does not allow the foot and ankle to properly support the body nor to properly absorb the impact forces. As motion continues forward, they will toe-off more from the ball of her foot. Runners who overpronate are susceptible to foot, ankle and knee problems if they don't wear a shoe that properly supports the motion of their feet.
There are many possible causes for overpronation, but researchers have not yet determined one underlying cause. Hintermann states, Compensatory overpronation may occur for anatomical reasons, such as a tibia vara of 10 degrees or more, forefoot varus, leg length discrepancy, ligamentous laxity, or because of muscular weakness or tightness in the gastrocnemius and soleus muscles. Pronation can be influenced by sources outside of the body as well. Shoes have been shown to significantly influence pronation. Hintermann states that the same person can have different amounts of pronation just by using different running shoes. It is easily possible that the maximal ankle joint eversion movement is 31 degrees for one and 12 degrees for another running shoe.
Not all foot injuries affecting runners are necessarily down to a particular running gait; it is rarely that simple to diagnose how a foot problem developed . Simply being an overpronator does not mean that a foot injury has been caused by the running gait and it could be due to a number of factors. However mild to severe overpronators tend to be at a higher risk of developing musculoskeletal problems due to the increased stresses and strains which are placed on the body when the foot does not move in an optimum manner. The following injuries are frequently due to overpronation of the feet. Tarsal tunnel syndrome. Shin splints. Anterior compartment syndrome. Plantar fasciitis. Achilles tendonitis. Bunions. Sesamoiditis. Stress fractures. Back and hip pain. Ankle pain.
When you overpronate your foot rolls inwards causing the lower leg to rotate inwards too. It's thought that this increases stress on the soft tissues of the lower leg causing pain and inflammation, or more commonly known as shin splints.
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.
Hyperpronation can only be properly corrected by internally stabilizing the ankle bone on the hindfoot bones. Several options are available. Extra-Osseous TaloTarsal Stabilization (EOTTS) There are two types of EOTTS procedures. Both are minimally invasive with no cutting or screwing into bone, and therefore have relatively short recovery times. Both are fully reversible should complications arise, such as intolerance to the correction or prolonged pain. However, the risks/benefits and potential candidates vary. Subtalar Arthroereisis. 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. HyProCure Implant. A stent is placed into a naturally occurring space between the ankle bone and the heel bone/midfoot bone. The stent realigns the surfaces of the bones, allowing normal joint function. Generally tolerated in both pediatric and adult patients, with or without adjunct soft tissue procedures. Reported removal rates, published in scientific journals vary from 1%-6%.