What causes whiplash?

What causes whiplash?

Whiplash is most commonly caused by a motor vehicle accident in which the car the person is riding in is not moving, and is struck from a vehicle from behind without notice. It is commonly thought the rear impact causes the head and neck to be forced into hyperextension as the seat pushes the person's torso forward - and the unrestrained head and neck fall backwards. After a short delay the head and neck then recover and are thrown into a hyperflexed position.

More recent studies investigating high-speed cameras and sophisticated crash dummies have determined that after the rear impact the lower cervical vertebrae (lower bones in the neck) are forced into a position of hyperextension while the upper cervical vertebrae (upper bones in the neck) are in a hyperflexed position. This leads to an abnormal S-shape in the cervical spine after the rear impact that is different from the normal motion. It is thought that this abnormal motion causes damage to the soft tissues that hold the cervical vertebrae together (ligaments, facet capsules, muscles).

The following video shows what happens during a "low speed collision"