Pronation or eversion is the inward roll of the foot while walking or running. Another way to look at pronation instead in terms of the degree of inward roll is in terms of where the foot pushes off at the end of each step, or at the end of the gait cycle. There are three main types of pronation in human gait: neutral pronation, overpronation, and underpronation or supination. While both overpronation and supination occur while walking and standing, they are usually more pronounced and the effects amplified while running. Those who overpronate tend to push off almost completely from the big toe and second toe. As a result, the shock from the foot?s impact doesn?t spread evenly throughout the foot and the ankle has trouble stabilizing the rest of the body. Additionally, an unnatural angle forms between the foot and ankle and the foot splays out abnormally. It is common even for people who pronate normally to have some angle between the foot and the ankle, but not to the extent seen in those who overpronate. In normal pronation the weight distributes evenly throughout the foot.
Over-pronation is very prominent in people who have flexible, flat feet. The framework of the foot begins to collapse, causing the foot to flatten and adding stress to other parts of the foot. As a result, over-pronation, often leads to Plantar Fasciitis, Heel Spurs, Metatarsalgia, Post-tib Tendonitis and/or Bunions. There are many causes of flat feet. Obesity, pregnancy or repetitive pounding on a hard surface can weaken the arch leading to over-pronation. Often people with flat feet do not experience discomfort immediately, and some never suffer from any discomfort at all. However, when symptoms develop and become painful, walking becomes awkward and causes increased strain on the feet and calves.
In addition to problems overpronation causes in the feet, it can also create issues in the calf muscles and lower legs. The calf muscles, which attach to the heel via the Achilles tendon, can become twisted and irritated as a result of the heel rolling excessively toward the midline of the body. Over time this can lead to inflexibility of the calf muscles and the Achilles tendon, which will likely lead to another common problem in the foot and ankle complex, the inability to dorsiflex. As such, overpronation is intrinsically linked to the inability to dorsiflex.
When you overpronate your foot rolls inwards causing the lower leg to rotate inwards too. It’s thought that this increases stress on the soft tissues of the lower leg causing pain and inflammation, or more commonly known as shin splints.
Non Surgical Treatment
Personal orthotics can be prescribed via your healthcare professional. If finances or insurance are issues, similar and often better options can be purchased online for overpronation. The right walking shoes are also essential. Most shoes cater to neutral foot gaits, unless they specifically state otherwise. That won?t help you if your foot rolls inward. In order to correct the issue, you need shoes with stability or motion control abilities, low heels, deep heel cups, and good arch support.
Calcaneal “Slide” (Sliding Calcaneal Osteotomy) A wedge is cut into the heel bone (calcaneus) and a fixation device (screws, plate) is used to hold the bone in its new position. This is an aggressive option with a prolonged period of non-weightbearing, long recovery times and many potential complications. However, it can and has provided for successful patient outcomes.