When a foot over-pronates stress is unduly placed on the inside of the ankle and the knee, and over a long period of time, particularly if a person is involved in sports and running, this added stress starts to damage structures in the knee and ankle. The result is usually pain, particularly when running, which typically varies in severity. If the arch of the foot is weak, usually due to a lack of strength in supporting muscles of the foot, it can collapse over time, so people who aren?t flat footed can sometimes start to over-pronate in time. This can stress tissues on the underside of the foot, causing painful conditions like bunions (the abnormal inflammation and protrusion of the big toe?s joint) and Plantar Fasciitis (painful inflammation of connective tissues in the sole of the foot).
Although there are many factors that can contribute to the development of these conditions, improper biomechanics of the body plays a large and detrimental role in the process. Of the many biomechanical elements involved, foot and ankle function perhaps contribute the most to these aches and pains.
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.
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
Pronation and supination are bio-mechanical problems, and are best treated and prevented with orthotic inserts. But before you run out to buy orthotics it makes sense to get the right advice on footwear, and the best advice I can give you, is to go and see a qualified podiatrist for a complete foot-strike and running gait analysis. They will be able to tell you if there are any concerns regarding the way your running gait is functioning. After your running gait has been analysed, have your podiatrist, or competent sports footwear sales person recommend a number of shoes that suit your requirements. Good quality footwear will go a long way in helping to prevent pronation and supination. And, if needed, invest in a pair of orthotic inserts to further prevent excessive pronation or supination.
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.