Whiplash
Medical Author: Jason C. Eck, DO, MS
Medical Editor: William C. Shiel, Jr., MD, FACP, FACR
What is whiplash?
Whiplash is a relatively common injury that occurs to a person's neck
following a sudden acceleration-deceleration force, most commonly from motor
vehicle accidents. The term "whiplash" was first used in 1928. The term "railway
spine" was used to describe a similar condition that was common in persons
involved in train accidents prior to 1928. The term "whiplash injury" describes
damage to both the bone structures and soft tissues, while "whiplash associated
disorders" describes a more severe and chronic condition.
Fortunately, whiplash is typically not a life threatening injury, but it can
lead to a prolonged period of partial disability. There are significant economic
expenses related to whiplash that can reach 30 billion dollars a year in the United
States, including:
- medical care,
- disability,
- sick leave,
- lost productivity, and
- litigation.
While most people involved in minor motor vehicle accidents recover quickly
without any chronic symptoms, some continue to experience symptoms for years
after the injury. This wide variation in symptoms after relatively minor
injuries has led some to suggest that, in many cases, whiplash is not so much a
real physiologic injury, but that symptoms are more created as a result of
potential economic gain. Many clinical studies have investigated this issue.
Unfortunately, while there will always be people willing to attempt to mislead
the system for personal gain, nevertheless, whiplash is a real condition with
real symptoms.
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).
Next: What are the symptoms of whiplash? »