Since you didn't include the picture i could be wrong but the most famous 'study of a woman's back' i know of is matisse.
The concept behind The Rite of Spring, developed by Roerich from Stravinsky's outline idea, is suggested by its subtitle, "Pictures of Pagan Russia in Two Parts"; the scenario depicts various primitive rituals celebrating the advent of spring, after which a young girl is chosen as a sacrificial victim and dances
There are many ways an artist can create a sense of movement in a piece of artwork, from blurring the back of a character to show movement, or showing the movement through air waves, arrows, and others. They can also make the character look like it is moving, and make the ground have more lines parallel to the movement, which will show movement.
hope this helps
Magic and also magic and you can almost use more magic.
