Pronation is a normal motion which occurs after heel strike during walking. As the foot moves towards toe off, the foot naturally should move from an outside path towards the midline of the body stopping at neutral in ideal conditions. Overpronation is the foot?s motion past neutral and moving excessively toward the bodies midline. Overpronation can be caused by a number of factors including internal rotation of the femur or thigh bone, internal torsion of the tibia or shin bone, being genu valgum or ?knock kneed?, as well as fixed deformities of the ankle and forefoot. The overpronating foot is often hypermobile meaning it has excessive range of motion in the foot joints.
There has been some speculation as to whether arch height has an effect on pronation. After conducting a study at the Rose-Hulman Institute of Technology, Maggie Boozer suggests that people with higher arches tend to pronate to a greater degree. However, the generally accepted view by professionals is that the most pronation is present in those with lower arch heights. To complicate matters, one study done by Hylton Menz at the University of Western Sydney-Macarthur suggests that the methods for measuring arch height and determining whether someone is ?flat-footed? or ?high-arched? are unreliable. He says, ?For this reason, studies investigating the relationship between static arch height motion of the rearfoot have consistently found that such a classification system is a poor predictor of dynamic rearfoot function.
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.
One of the easiest ways to determine if you overpronate is to look at the bottom of your shoes. Overpronation causes disproportionate wear on the inner side of the shoe. Another way to tell if you might overpronate is to have someone look at the back of your legs and feet, while you are standing. The Achilles tendon runs from the calf muscle to the heel bone, and is visible at the back of the ankle. Normally it runs in a straight line down to the heel. An indication of overpronation is if the tendon is angled to the outside of the foot, and the bone on the inner ankle appears to be more prominent than the outer anklebone. There might also be a bulge visible on the inside of the foot when standing normally. A third home diagnostic test is called the ?wet test?. Wet your foot and stand on a surface that will show an imprint, such as construction paper, or a sidewalk. You overpronate if the imprint shows a complete impression of your foot (as opposed to there being a space where your arch did not touch the ground).
Non Surgical Treatment
Anti-Pronation Insoles provide a unique foot support system that aligns the lower body. The major cause of foot and leg pain is over pronation (rolling over of the feet) which causes excessive pressure on the muscles, ligaments and bones of the lower body. Running insoles treat the underlying cause of over pronation and prevent future occurrences of the associated foot or leg condition. A project conducted at the NIKE Sport Research Laboratory studied the effects of orthotics on rear foot movement in running. Nine well-trained runners who wore orthotics were chosen as subjects. The results of the study indicated that orthotics reduced rear foot movement by roughly one degree or approximately nine percent of the amount found in runners not using orthotics. The average reduction of the maximum velocity of pronation was fifteen percent. Thus this study indicates that orthotics and insoles control over pronation which will treat and prevent many sporting injuries.
Firstly, a thorough and correct warm up will help to prepare the muscles and tendons for any activity or sport. Without a proper warm up the muscles and tendons around your feet, ankles and lower legs will be tight and stiff. There will be limited blood flow to the lower legs, which will result in a lack of oxygen and nutrients for those muscles. Click here for a detailed explanation of how, why and when to perform your warm up. Secondly, flexible muscles are extremely important in the prevention of most ankle and lower leg injuries. When muscles and tendons are flexible and supple, they are able to move and perform without being over stretched. If however, your muscles and tendons are tight and stiff, it is quite easy for those muscles and tendons to be pushed beyond their natural range of motion. To keep your muscles and tendons flexible and supple, it is important to undertake a structured stretching routine.