Pronation occurs as weight is transferred from the heel to the forefoot and the foot rolls inwards. Or to put it a little more technically; pronation is the movement of the subtalar joint (between the talus and calcaneus) into eversion, dorsi flexion and abduction (turning the sole outwards, upwards and sideways). A certain amount of this is natural but it many people the foot rolls in too much or over pronates.
Excess stress on the inner surface of the foot can cause injury and pain in the foot and ankle. Repeated rotational forces through the shin, knee, thigh and pelvis also place additional strain on the muscles, tendons and ligaments of the lower leg.
Because pronation is a twisting of the foot, all of the muscles and tendons which run from the leg and ankle into the foot will be twisted. In over-pronation, resulting laxity of the soft tissue structures of the foot and loosened joints cause the bones of the feet shift. When this occurs, the muscles which 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. Injuries due to poor biomechanics and twisting of these muscles due to over-pronation include: 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). Foot problems due to over-pronation include: bunions, heel spurs, plantar fasciitis, fallen and painful arches, hammer toes, and calluses.
If you have flat feet or low arches, chances are you overpronate. Although not always the case, the lower your arches the greater the overpronate. Stand on a hard surface (in front of a mirror if you need to) and look at your feet, flat feet or low arches are easy to spot. If your feet look flatter than a pancake, have a look at your ankles and see if they seem collapsed or straight. If they are, you’re overpronating.
Non Surgical Treatment
Over-Pronation can be treated conservatively (non-surgical treatments) with over-the-counter orthotics. These orthotics should be designed with appropriate arch support and medial rearfoot posting to prevent the over-pronation. Footwear should also be examined to ensure there is a proper fit. Footwear with a firm heel counter is often recommended for extra support and stability. Improper fitting footwear can lead to additional problems of the foot.
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.