Jumping jack

Physical jumping exercise

A jumping jack, also known as a star jump and called a side-straddle hop in the US military, is a physical jumping exercise performed by jumping to a position with the legs spread wide. The hands go overhead, sometimes in a clap, and then return to a position with the feet together and the arms at the sides. The jumping jack exercise's origin is said to date back to 1885 as a method of hazing underclassmen at West Point Military Academy by John J. "Black Jack" Pershing, who is said to have developed it.

From Wikipedia, under CC BY-SA. More on occurri.