trauma to the back. in other words, a laceration a significant contusion, which is manifested externally on the skin and then the underlying subcutaneous tissue. keep in mind a little basic anatomy here. the spinal cord is contained within the bone. you have the vertebral body of each vertebrae in front of you and you have the spinous process behind you and you have lateral or transverse processes to the side. so the cord is protected by bone. in order for the cord to undergo severance of 80%, not only do you have a fracture but you've got severe displacement of the fracture. and i have not seen that kind of vertebral fracture except in high speed motor vehicular collisions or people falling from high -- a high ediface or