What is whiplash from a car accident and when is it evident or not evident?

Greg Stokes: What usually happens in a car crash is there is sudden, violent movement to the neck and the spine. If you picture the head as a bowling ball that weighs about six or seven pounds and you picture this all happening within about 300 milliseconds, the G forces are pretty severe on the cervical spine. Many times there are going to be ripped ligaments. There could be damage to the discs. What is