SIENNA Miller injured herself while filming her new movie G.I. Joe: The Rise of Cobra - just by walking down the street I didnt injure myself in the action scenes, she says. But just walking down the street I had some mild incident. I slipped on a rubber bullet and I had to go to the hospital because my hand blew up. This is not anything to do with the film, its my general clumsiness. I fight in 6-inch heels so its a precarious situation to begin with. I slipped over and then I ran over an explosion at the wrong time. These things happen. G.I. Joe: The Rise of Cobra hits movie theaters in August this year. Miller, 27, recently revealed that shes insecure about her body. Im lucky Ive got a good metabolism, she said. Im very grateful for that. But Im not toned at all. I think Ive reached an age at 27 where its time for me to start working out a bit. I cant get away with it any more. I used to be quite firm and tiny and, as I hit 25, things started to change. Now Im 27 Im noticing more changes - bare legs at the top and back is not a pretty sight. Im lazy and if I wear clothes, its hidden well. I dont feel like a beauty icon. I get pretty insecure and have the same insecurities as everyone else - sometimes more because there is more focus put on me. - SS