Flat feet, also called pes planus or fallen arches, is a condition in which the arch of the foot collapses, with the entire sole of the foot coming into complete or near-complete contact with the ground. In some individuals (an estimated 20-30% of the general population) the arch simply never develops in one foot (unilaterally) or both feet (bilaterally). It should be noted that being flatfooted does not decrease footspeed. Horses can also develop flat feet