Feet are supposed to roll inward as a part of every step you take. This helps them to mold to the various terrain that they step on (sand, rocks, various obstacles) without injury. This is called pronation. But, when your feet roll inward excessively, problems often arise. Excessive inward rolling of the feet and ankles is called over-pronation. Sometimes, people who over-pronate are told they have ?flat feet?. The term ?flat feet? can be misleading. When standing, body weight causes the arch of most feet to flatten out somewhat. This does not mean they become flat like pancakes (though some feet do). Instead, the arch shape gets longer and flatter and the arch height gets lower.
Unless there is a severe, acute injury, overpronation develops as a gradual biomechanical distortion. Several factors contribute to developing overpronation, including tibialis posterior weakness, ligament weakness, excess weight, pes planus (flat foot), genu valgum (knock knees), subtalar eversion, or other biomechanical distortions in the foot or ankle. Tibialis posterior weakness is one of the primary factors leading to overpronation. Pronation primarily is controlled by the architecture of the foot and eccentric activation of the tibialis posterior. If the tibialis posterior is weak, the muscle cannot adequately slow the natural pronation cycle.
People with overpronation may suffer from pain in the knees, hips, and low back. Overpronation itself does not necessarily cause any other symptoms but is a contributing factor of many foot conditions such as Plantar Facsiitis, Heel Spur Syndrome, Posterior Tibialis Tendon Rupture or Tendonitis, Hallux Valgus, Bunion Deformities, Metatarsalgia, Hallux Limitus or Hallux Rigidus, Hammer Toes, and Morton?s Neuroma.
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
Supportive orthotics in the shoe is a method commonly implemented to treat many common running injuries associated with pronation. An advantage of orthotics is that they often allow the sufferer to continue to participate in athletic activity and avoid other treatment options that could be potentially costly and time consuming. Seventy-five percent of injured runners are successfully treated with the prescription of orthoses. Orthotics are the most effective treatment for symptoms that develop from unusual biomechanics within the body such as overpronation, resulting in either great improvement or complete healing of the injury in about half the cases.
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.