Pronation refers to the inward roll of the foot during normal motion and occurs as the outer edge of the heel strikes the ground and the foot rolls inward and flattens out. A moderate amount of pronation is required for the foot to function properly, however damage and injury can occur during excessive pronation. When excessive pronation does occur the foot arch flattens out and stretches the muscles, tendons and ligaments underneath the foot.
Over-pronation may happen because the tissue that attaches to your foot bones is loose. You may be born with this problem or it may result from injuries or overuse, like from too much running.
Overpronation can lead to injuries and pain in the foot, ankle, knee, or hip. Overpronation puts extra stress on all the bones in the feet. The repeated stress on the knees, shins, thighs, and pelvis puts additional stress on the muscles, tendons, and ligaments of the lower leg. This can put the knee, hip, and back out of alignment, and it can become very painful.
Look at the wear on your shoes and especially running trainers; if you overpronate it's likely the inside of your shoe will be worn down (or seem crushed if they're soft shoes) from the extra strain.
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.
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.