This doesn't do much for me as a photo - the colors are pointless to me, i can't understand why it should have a purple hue to it. some photos work ell with it, but a back doesn't seem to cut the mustard.
Also the pose and location isn't very dramatic - being flat on is kind of depth less and boring.
I would suggest rotating 45 degrees next time, and casting some shadows and depth.
I'm having a problem finding anything particularly interesting in this composition. Maybe if it was not underexposed, the muscle/texture detail would be a stronger element of the image. The color itself is not really strong enough to support the entire theme.