cage on the far right side of my waist. it doesn't hurt all of the time, and isn't bad, but for instance if i sit up and stretch foward it starts to hurt, or if i sit in certain positions, yesterday when i was sitting i thought i had pulled a muscle because i turned at a funny angle and i had a sharp pain where i am having my pain now, but i didnt have this yesterday after i thought i pulled a muscle it has only just started a few hours ago! could it just be a pulled muscle?