Flat feet are a common condition, especially in infants and toddlers, as the longitudinal arch is not developed and flat feet are normal. The arch develops in childhood, and by adulthood, most people have developed normal arches. Most feet are flexible and an arch appears when the person stands on his or her toes. Stiff, inflexible or painful flat feet may be associated with other conditions and require medical attention.
Most flat feet usually do not cause pain or other problems. Flat feet may be associated with pronation, a leaning inward of the ankle bones toward the center line. Shoes of children who pronate, when placed side by side, will lean toward each other (after they have been worn long enough for the foot position to remodel their shape). Foot pain, ankle pain or lower leg pain, especially in children, may be a result of flat feet and should be evaluated.
Painful progressive flat foot, otherwise known as Tibialis Posterior Tendinitis, is caused by inflammation. The tendon becomes inflamed, stretched or suffers a partial or total tear. If left untreated, this condition may lead to severe disability and chronic pain. Some people are prone to this condition if they have flat feet or an abnormal attachment of the tendon to the bones in the midfoot.