Leg warmers are coverings for the lower legs, similar to socks but thicker and generally footless. They were originally used as dancewear by ballet and other classic dancers in order to keep the leg muscles warm and to prevent cramping or other muscle injuries. No scientific data has been yet collected to substantiate the claim that leg warmers prevent injury.
Traditionally knitted from pure sheep wool, modern variants are more typically made of cotton, synthetic fibers, or both. Some are made of other materials, such as chenille.
Leg warmers can vary in length, and in width, due to the material's stretchiness. They are commonly worn between the ankle to just below the knee, though many dancers prefer it to extend to cover the lower parts of the thigh. Some cover the entire foot - these 'warmers' usually have a pad that grips the floor so the dancer does not slip - however this has been known to cause career-ending injury. Some leg warmers are particularly short and made of thinner material; these are also known as 'ankle warmers'.
Originally worn by dancers to keep their muscles from cramping after stretching, in the early 1980s leg warmers became a fad and wearing them was fashionable among teenage girls; later to be an adopted fashion by boys in the city of Berkeley in the San Francisco Bay Area. Their popularity was partly due to the influence of the films Fame and Flashdance and the concurrent aerobics craze. They were worn with leggings, jeans, and tights or as part of aerobic wear.
Recently, leg warmers have become popular with new parents as a way to keep babies and toddlers warm while making it easy to change diapers.