After many years of research, medical science is only now starting to truly explain why some people seem to have long-term neck pain after a rear end car accident.
Several studies seem to suggest that the culprit is the facet joints .
Another study by Panjabi showed that a suspicious s-shaped curve seems to form in the neck during a rear end impact. In the example above, notice how at the apex of the S, the blow-up of the facet joints shows one spearing the other. This has now been confirmed by live volunteers in a more recent study.