Hula hoops were the rage during the late 50s and 60s. Looks like this young lady has been pratcing a lot. Here is the Wikipedia explaination: A hula hoop is a toy hoop, usually made of plastic, that is twirled around the waist, limbs, or neck. Although the exact origins of hula hoops are unknown, children around the world have played with hoops, twirling, rolling and throwing them throughout history. Hula hoops generally measure approximately 28 inches in diameter. Traditional materials for hoops include willow, rattan (a flexible and strong vine), grapevines and stiff grasses. Today, they are often made of plastic tubing.