so I slammed the shit out of my right shin. I thought maybe it was even broken.  but the ER said no.  it was really weird and cool and freaky - like immediately after I banged my leg, this big blue puffy spot formed under my skin right on my shinbone.  about 4 inches long and stood out from my leg about half an inch. It was blood pooling under my skin right on the bone.  I never saw anything like that before.  I just stuck my hand on it and pressed really hard, to keep all my blood from leaking out.