A whiplash accident occurs when one motor vehicle strikes another from behind, causing certain forces to be transmitted from the striking vehicle to the struck vehicle. These forces are then transmitted to the occupant(s) of the struck vehicle, where they have the potential to cause whiplash injury.
Research both in the Biomechanics Laboratory at Yale University in New Haven and in live crash tests using human volunteers has shed relatively new light on the contortions the cervical spine (neck) undergoes as a result of impact culminating in whiplash.