Pronation
Pronation is the most common and damaging medical problem that may occur as a result of flat arches. Pronation is a turning outward of the foot at the ankle, so that one has a tendency to walk on the inner border of the foot. You can test for pronation by looking at the leg and foot from the back. Normally you can see the Achilles Tendon run straight down the leg into the heel. If the foot is pronated, the tendon will run straight down the leg, but when it lies on the heel, it will twist outward. This makes the inner ankle bone much more prominent than the outer ankle bone. 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. If left untreated, pronation may be the cause of heel spurs, plantar fasciitis, frequent ankle sprains, shin splints, weak and painful arches, and eventually knee, hip, and lower back pain.