How to Bust a Move, 1856

animated image of man doing calisthenics poses that look oddly like Saturday Night Fever moves

Throw the body and stretch the right arm and right leg as far as possible to the right. Reverse the movement, and stretch them to the left, as at Fig. 54. Count one at the first movement, and so on to twelve.

Catharine E. Beecher, Physiology and Calisthenics for Schools and Families

Have you been trying to figure out Travolta’s moves since 1977? Surprisingly, the secret is contained in this nineteenth-century manual of calisthenics.