Pronation is the natural act of the body spreading the impact of walking, jogging or running throughout the foot evenly. As the foot strikes the ground, the ankle naturally rolls inward absorbing the shock of the ground and mobilizing to the terrain. Overpronation is when the ankle of the foot rolls in past its normal 15? of inward rotation. The cause of this could be many things such as foot type, biomechanics, or compensation strategies. People with flat feet often, although not always, overpronate.
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.
If you cannot afford to get a proper gait analysis completed, having someone observe you on a treadmill from behind will give you an idea if you are an overpronator. It is possible to tell without observing directly whether you are likely to be an overpronator by looking at your foot arches. Check your foot arch height by standing in water and then on a wet floor or piece of paper which will show your footprint. If your footprints show little to no narrowing in the middle, then you have flat feet or fallen arches. This makes it highly likely that you will overpronate to some degree when running. If you have low or fallen arches, you should get your gait checked to see how much you overpronate, and whether you need to take steps to reduce the level to which you overpronate. Another good test is to have a look at the wear pattern on an old pair of trainers. Overpronators will wear out the outside of the heel and the inside of the toe more quickly than other parts of the shoe. If the wear is quite even, you are likely to have a neutral running gait. Wear primarily down the outside edge means that you are a supinator. When you replace your running shoes you may benefit from shoes for overpronation. Motion control or stability running shoes are usually the best bet to deal with overpronation.
Non Surgical Treatment
Although there is no actual cure for over-pronation it is possible to correct or at least reduce this problem. In order to restore our normal foot function an 'orthotic' or orthotic insole device is placed inside the shoes. Orthotics are designed to realign the foot and ankle bones to their natural position. This in turn restores our normal foot function and it helps alleviate not only foot problems but also ailments in other parts of the body i.e. the legs, knees and lower back. In addition to wearing an orthotic, it is recommended to wear supportive shoes, like good quality athletic footwear with a firm heel counter and sufficient flexibility in the forefoot area.
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%.