A shimmy or shoulder shakes is a dance move in which the body is held still, except for the shoulders, which are quickly alternated back and forth. When the right shoulder goes back, the left one come
1918 sheet music "Everybody Shimmies Now" with Mae West
When the Alamo Theater in Atlanta used a cutout display of Viola Dana with separately mounted shoulders and a mechanism to do a shimmy for the film The Chorus Girl's Romance (1920), the chief of police ordered the mechanism turned off.
Flappers were a subculture of young Western women prominent after the First World War and through the 1920s who wore knee-length skirts, bobbed their hair, listened to jazz, and flaunted their disdain
Shimmy
…written by Clarence Williams and Armand Piron, and published in 1919, which has been popular ever since and performed and recorded by many artists. Flappers often performed the dance in the 1920s. The origin of the name is often falsely attributed to Gilda Gray, a Polish emigrant to America. An anecdote…
Actress Louise Brooks (1927)
A flapper on a ship (1929)
Violet Romer in a flapper dress c. 1915
An advertisement for the 1920 silent film comedy The Flapper, with Olive Thomas, before the look of the flapper had started to coalesce.