front of the face? does that lead somebody to think maybe he was hurt in the front as well, or the impact would actually resound in that way? >> and that's exactly a great question. you have to understand the underlying mechanisms. and if i can just explain it as simply as possible, he fell to the back of his head where i'm pointing. that's a lot of force, okay. fell or had an impact, whatever it may be. there was a lot of force generated. it rubbed away the surface of the skin. but that force now goes through the skull. it radiates around. and the brain is also within a fixed box, which is a hard box. now the impact goes from the back to the front. and so if you think about sort of like an eggshell in a way, there is thinner parts of the skull that cracked which are towards the front, and the brain is actually pushed from the back to the front and pushed back again. and so that movement is injuring