Wheel gymnastics

Wheel gymnastics is a form of gymnastics which originated in Germany.
Wheel gymnasts do exercises in a large wheel known as the "Rhönrad", "gymnastics wheel", "gym wheel", or "German wheel".
There are three main categories of exercise in wheel gymnasts. They are: "straight line", "spiral", and "vault".
History.
While being a child, Otto Feick, the son of a blacksmith from Reichenbach, Germany, used to roll down a hill in two wagon tires which inspired him later to invent the wheel gymnastics between 1920-1922. The current wheel gymnastics obtained its final shape in 1974 with the introduction of the PVC coating. Now, it's a competitive sport practiced in Belgium, Denmark, Netherlands, Austria, Switzerland, Japan, and United States of America.