Your Back.. By Yourself?
Hellpp.. he he he I want to crack it =]
Twist your upper body both ways, but it might not work, it's kinda hard to crack your back by yourself. You could also hang from a bar if you have one available, just relax your whole body and let gravity pull on it...if your back is overdue for a crack, that will definetly do it.
if you have a chair in your house that the back doesnt come up to high then position yourself so the mid section of your back is lined with the top of the chair and lean back sounds weird but it works lol