The American Quarter Horse is an American breed of horse who excels at sprinting short distances. His name came from his ability to out-run other horse breeds in races of a quarter of a mile or less. Some Quarter Horses have been clocked as moving at speeds of up to 88.5km/hr. 

American Quarter Horses are also great at changing direction quickly making them ideal for barrel racing and cutting and reining. 

Generally speaking, American Quarter Horses have very muscular hindquarters.