Pronation, in anatomical terms, means to rotate, and it applies to any rotational movement of a bone. Pronation in the feet involves an inward rolling of the foot throughout the gait which helps with the transfer of force. Normally the foot will move from the heel to the toes with only a small degree of pronation, with a slight inward roll from the outside of the heel to the inside of the foot which helps to support the body weight. Normal pronation involves the rolling of the foot to approximately 15 degrees. If you have normal foot arches, you are likely to be a neutral runner and will most likely pronate normally.
Flat feet don't automatically mean you have a problem. The problem can be divided into a flexible flat foot or rigid flat foot. The rigid flat foot is one that does not change shape when the foot becomes weight bearing. i.e. it does not go through the excessive motion of pronation. Generally speaking this foot does not provide too many problems. The flexible flat foot is the type that when it becomes weight bearing the foot and ankle tends to roll in (pronates) too far. This type of person will often say I have great arches but when I stand up much of this arch disappears as the foot excessively pronates When the foot is excessively pronating and causing problems like sore ankles, feet or knees when standing or exercising then arch support is extremely important to restore the foot structure.
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.
A quick way to see if you over-pronate is to look for these signs. While standing straight with bare feet on the floor, look so see if the inside of your arch or sole touches the floor. Take a look at your hiking or running shoes; look for wear on the inside of the sole. Wet your feet and walk on a surface that will show the foot mark. If you have a neutral foot you should see your heel connected to the ball of your foot by a mark roughly half of width of your sole. If you over-pronate you will see greater than half and up to the full width of your sole.
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.
The MBA implant is small titanium device that is inserted surgically into a small opening between the bones in the hind-mid foot: the talus (ankle bone) and the calcaneus (heel bone). The implant was developed to help restore the arch by acting as a mechanical block that prevents the foot from rolling-in (pronation). In the medical literature, the success rate for relief of pain is about 65-70%. Unfortunately, about 40% of people require surgical removal of the implant due to pain.