Skateboards consist of three main parts: the board, called a deck; the axle assembly, or truck; and the four wheels. Skateboards are available in a wide variety of designs and materials. A skillful skateboarder is capable of performing tricks and creative movements, such as turning, spinning, traveling backward and forward, sitting, kneeling, balancing on one or two hands, and jumping over obstacles.
Skateboarding has been criticized for being dangerous, and each year thousands of skateboarding injuries occur in the United States. The American National Skateboard Association, a nonprofit organization headquartered in San Bernardino, Calif., is committed to standardizing competitions and the criteria for judging contests and tournaments.
The original skateboards were merely wooden planks to which roller-skate wheels were attached. It was not until the 1970s, when Frank Nasworthy of California devised a truck with smooth-rolling urethane wheels, that skateboarding flourished, reaching its greatest popularity during the late 1970s.
