Flatfeet: A condition of the feet in which the arch of the instep is flattened and the entire sole touches the ground. The Latin term pes plans is used to denote flat foot.
All babies have flat feet because their arches are not yet built up (and their feet tend to be plump). This condition may persist into adulthood, or an arch may form as the child grows.
Flat feet can also be acquired, as in jobs that require a great deal of walking and carrying heavy objects.
People with flat feet sometimes experience clumsiness and fatigue from prolonged walking or running. Wearing shoes with built-in arch supports can help. People with weakness in the ankle as well as flat feet may find that their feet turn in or roll toward the middle, damaging shoes and causing discomfort. Shoes with both built-in arch supports and rigid counters (side supports) are helpful. Exercises may also be useful in reducing discomfort.