Just think of the extreme pain and agony of a simple wound, and times that suffering by 10. The pain is so great, you scream without choice. Just the simple impulse, and pain propels you to do so. Tears stream out of your eyes from the mere pressure of hurt, and blood spills from your wound, trying to fix the problem. You instantly clamp your hands down on the stubbed end, and your bone had ripped, and shattered off in a crooked spiky manner. Joints and ligaments and veins hang loosely and torn from the end, and flesh has been mangled about in heap of bloody suffering.
I think I went a little too far there...