Over Pronation (Flat Feet) refers to the biomechanical shock-absorbing motion of the ankle, foot and lower leg. It is the natural inward flexing motion of the lower leg and ankle. Standing, walking, and running cause the ankle joint to pronate which in turn helps the body to absorb shock and allows it to control balance. An ankle joint that is too flexible causes more pronation than desired. This common condition is called Over- Pronation (sometimes referred to as "Flat Feet"). This foot condition places an extreme degree of strain on various connective tissues of the ankle, foot, and knee. If this condition is not addressed foot pain and toe deformities such as bunions and hammer toes (just to name a couple) may develop. Hip and lower back pain may also be residual results from this condition.
There are many biomechanical issues that can contribute to excessive pronation, including weak foot intrinsic muscles, limited ankle dorsiflexion mobility and calf flexibility, weak ankle invertor muscles (e.g. posterior tibialis), weak forefoot evertor muscles (peroneus longus), poor hip strength and control, Anterior pelvic tilting, heel InversionIn a person who overpronates, the heel bone goes into an everted position meaning that it turns out away from the midline of the body. The opposite motion of eversion is inversion. Inversion is a motion that needs to be controlled to prevent the foot from excessively pronating.
Because overpronation affects the entire lower leg, many injuries and conditions may develop and eventually cause problems not only in the leg and foot, but also the knee, hips and lower back. Pain often begins in the arch of the foot or the ankle. Blisters may develop on the instep, or on the inside edge of the heels. As overpronation continues and problems develop, pain will be felt elsewhere, depending on the injury.
The best way to discover whether you have a normal gait, or if you overpronate, is to visit a specialty run shop, an exercise physiologist, a podiatrist or a physical therapist who specializes in working with athletes. A professional can analyze your gait, by watching you either walk or run, preferably on a treadmill. Some facilities can videotape your gait, then analyze the movement of your feet in slow-motion. Another (and less costly) way is to look at the bottom of an older pair of run shoes. Check the wear pattern. A person with a normal gait will generally see wear evenly across the heel and front of the shoe. A person who overpronates will likely see more wear on the OUTside of the heel and more wear on the INside of the forefoot (at the ball). A person who supinates will see wear all along the outer edges of the shoe. You can also learn about your gait by looking at your arches. Look at the shape your wet feet leave on a piece of paper or a flat walking surface.
Non Surgical Treatment
The following exercises help retrain the foot and ankle complex to correct overpronation. Exercises may be performed while wearing shoes, or for an even greater challenge, in bare feet. Duck Stand. This exercise is designed to prepare for the more dynamic BT exercises ahead by waking up the gluteal muscles and teaching clients how the gluteal muscles control the degree of foot pronation. For example, when the glutes contract concentrically, they rotate the leg outward. As the leg rotates outward, the arch of the foot raises (i.e., supinates). Stand beside the BT with both heels together and feet turned outward. (Note: As you progress, perform this exercise while standing on the BT.) Try to rotate legs outward by tightening buttock muscles while tilting pelvis under. As legs rotate outward, arches of the feet raise up out of pronation. Hold position for 30 seconds. Big Toe Pushdowns. This exercise is designed to strengthen the muscle of the big toe that holds up the arch of the foot (i.e., flexor hallucis longus muscle). This stops the foot from overpronating. Stand on top of the BT dome with feet facing forward. Use gluteal muscles to raise the arches of the feet (see previous exercise - "Duck Stand"). Keep arches raised while pushing down big toe into the BT. While pushing down, tension build in the arch on the underside of their foot should be felt. Hold position for 15 seconds.
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.