NFL Player's Pads

I'm watching the Seahawks - Bears game, and something that has bugged me in the past came to mind again. I can't believe how few pads these guys are wearing! None of them are wearing knee pads, thigh pads or hip pads. I haven't noticed any arm pads or elbow pads either. From what I can see, they are only wearing a flak jacket, shoulder pads and helmet.