Flatfoot is a common condition that occurs in both children and adults. Many people with flat feet do not experience pain or other problems. When pain in the foot, ankle, or lower leg does occur the feet should be evaluated. Although there are various forms of flatfoot, they all share one characteristic - partial or total collapse of the arch. Other characteristics of a flatfoot that one can observe are the tilting of the heel toward the outside, inward leaning of the ankle, tight heel cord, bunion and hammertoe deformities, and the outward drifting of the forefoot and toes.

In infants and toddlers, prior to walking, the medial longitudinal arch has not yet developed and flat feet can be normal. The arch should slowly develop as the child begins to walk. When a flatfoot persists in early childhood it is referred to as "pediatric flatfoot." Symptoms associated with a pediatric flatfoot may include pain in the arch, heel, ankle, and outside of the midfoot. The child may also experience pain along the shin bone, knee joint and lower back. Complaints of soreness or fatigue in the foot and leg are not uncommon in a severe pediatric flatfoot.

Adult-acquired flatfoot, otherwise known as posterior tibial tendon dysfunction, develops most commonly in adults with an unstable or flexible arch leading to a painful progressive flatfoot. This condition arises when a tendon or ligament in the foot becomes inflamed, stretched or torn. This condition may lead to severe disability and chronic pain if left untreated.

Treatment for painful flatfoot may include nonsteroidal anti-inflammatory medications, icing, physical therapy, supportive taping, bracing, and orthotics. In some cases, surgery may be necessary to reconstruct the arch to restore normal function.