One of the main postural deviations that cause pain and injury in the foot and ankle area (and resultant compensations in the rest of the body) is overpronation. Pronation is a normal function that occurs when the foot rolls inward toward the midline of the body. This movement causes the heel to collapse inward and the medial arch of the foot to elongate and flatten. Overpronation, however, is when the foot collapses too far inward for normal function. Consequently, this directly affects the ability of the foot to perform and can disrupt proper functioning through the entire body.
There is a relationship between biomechanics and injury that is specific to each body part. Overall though, poor mechanics will either increase the landing forces acting on the body or increase the work to be done by the muscles. Both increase the stress, which, depending on the individual and the amount of running can become excessive and cause injury.
Due to the laxity of the soft tissue structures of the foot, and the fact that the joints are not held together properly, the bones of the feet shift. When this occurs, the muscles that attach to these bones must also shift, or twist, in order to attach to these bones. The strongest and most important muscles that attach to our foot bones come from our lower leg. So, as these muscles course down the leg and across the ankle, they must twist to maintain their proper attachments in the foot. This twisting of these muscles will cause shin splints, Achilles Tendonitis, generalized tendonitis, fatigue, muscle aches and pains, cramps, ankle sprains, and loss of muscular efficiency (reducing walking and running speed and endurance). The problems we see in the feet, which are due to over-pronation include bunions, heel spurs, plantar fasciitis, fallen and painful arches, hammertoes, metatarsalgia (ball of foot pain), and calluses.
Firstly, look at your feet in standing, have you got a clear arch on the inside of the foot? If there is not an arch and the innermost part of the sole touches the floor, then your feet are over-pronated. Secondly, look at your running shoes. If they are worn on the inside of the sole in particular, then pronation may be a problem for you. Thirdly, try the wet foot test. Wet your feet and walk along a section of paving and look at the footprints you leave. A normal foot will leave a print of the heel, connected to the forefoot by a strip approximately half the width of the foot on the outside of the sole. If you?re feet are pronated there may be little distinction between the rear and forefoot, shown opposite. The best way to determine if you over pronate is to visit a podiatrist or similar who can do a full gait analysis on a treadmill or using forceplates measuring exactly the forces and angles of the foot whilst running. It is not only the amount of over pronation which is important but the timing of it during the gait cycle as well that needs to be assessed.
Non Surgical Treatment
Over-pronation and the problems that go with it are treated with shoe inserts called arch supports or orthotics. You can buy orthotics at a pharmacy or athletic shoe store or they can be custom made. Make sure the arch supports are firm. If you can easily bend them in half, they may be too flexible.
Subtalar Arthroereisis. Primary benefit is that yje surgery is minimally invasive and fully reversible. the primary risk is a high chance of device displacement, generally not tolerated in adults.
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.