Neck Pain Whiplash

Whiplash and Chiropractic
It is perhaps not surprising that, in the contentious medicolegal environment of
neck pain whiplash in general, and low speed impact related injuries in particular, experts from
fields outside of chiropractic and medicine are frequently called upon to address issues
that are not generally within the purview and scope of knowledge of health care
practitioners. The most common issues facing these experts relate to causation–i.e.,
which driver was at fault–and the forces or loads experienced by the occupants of the
involved vehicles.
Auto crash reconstructionists are (usually) specially trained people who can
frequently determine causation using a number of sophisticated and, frequently,
ingenious methods. [For the purposes of this newsletter, and in light of the recent
decision by the National Highway and Traffic Safety Administration (NHTSA) to
abandon the term “accident” in favor of “crash” (accident may foster a non-preventable
fatalistic view of car crashes which may diminish crash prevention strategies), I’ll refer
to them henceforth as auto crash reconstructionists (ACRs).] This notion was also
recently promoted by the British Medical Journal. In order to arrive at meaningful
conclusions, however, the ACR requires tangible evidence. This might come in the form
of scaled police drawings, eye witness accounts, photographs, actual inspection of the
involved vehicles, or photographs of the crash scene showing skid marks, gouges in the
roadway, debris, etc. Naturally, the quality of the outcome parallels the quality of the
input, and this becomes a defining statement in ACR Neck Pain Whiplash.
The second issue–forces and loads experienced by the vehicle occupants, and the
likelihood of injury–is usually more problematic than issues of causation or liability.
There are two reasons for this statement: Neck Pain Whiplash
1) by attempting to calculate these values, it is tacitly implied that the forces to the
occupant can be reliably estimated once the collision velocity and other variables have
been estimated, 2) there is an implicit assumption that the ACR (or some expert at least)
can use this information to reliably estimate the chances for actual occupant injury, and,
in many instances, to gauge the likely severity of that injury or injuries.
The stark truth of the matter is that, even in the best of cases, the most that an
ACR can usually provide is a fairly broad range of estimates of closing velocity (i.e.,
impact velocity in the case of a vehicle striking a stationary target), changes in velocity
(usually referred to as delta ( ) V or V), and acceleration.
Law of Inertia. Simply stated in the context of Whiplash trauma, things at rest
tend to remain at rest, and different parts of the same object can have different inertias.
The human body has two large parts that have their own separate inertia, the
trunk and the head. These two large pieces of inertia mass (the head and the trunk) are
connected by the thinner structure of the cervical spine. During a motor vehicle
collision, a vehicle that is struck from behind will quickly move forward. As the vehicle
moves forward, so do the passengers seats in the vehicle. As the passenger seat moves
forward, so does the trunk of the passenger sitting in the seat. However, the head the
head of the passenger in the seat does not move forward because the head has a separate
inertia from the trunk. As the vehicle, the seat, and the trunk move forward from the
collision, the head remains at rest, forcing the neck backwards. The result is an inertial
injury to the soft tissues of the vertebral joints of the cervical spine. Importantly, the
neck does not hit anything; it sustains an inertial injury, similar to that seen in shaken
baby syndrome.

Neck Pain Whiplash
The type of injuries chiropractors treat that result from rear impact motor vehicle
collisions are classified as “inertial acceleration injuries.” Popular terminology within
our profession is “cervical acceleration / deceleration syndrome,” or CAD (Foreman and
Croft). These inertial acceleration injuries to the cervical spine are proportional to the
acceleration achieved by the struck vehicle. The greater the acceleration of the struck
vehicle, the greater the acceleration injuries to the cervical spine structures.
Importantly, sufficient vehicle acceleration to cause cervical spine inertial acceleration
injuries can occur with no or minimal vehicle structural damage. This concept is
adequately explained by Robbins (Journal of the Society of Automotive Engineers, 1997)
and others, below. Robbins article is titled:
Lack of relationship between vehicle damage and occupant injury
In agreement with above, Robbins states, that injury is linked to the magnitude of
the acceleration achieved by the struck vehicle. Acceleration is expressed in the units of
“G” which stands for the acceleration of gravity. Falling in gravity is not a velocity (a
steady speed); it is an acceleration (going faster every second). 1G = 9.81
meters/second² (m/s²). Robbins states the pertinent mathematical formula is from the
great Italian physicist, mathematician, and astronomer, Galileo (d. 1642) Neck Pain Whiplash :
A = V²/2s
a = acceleration
V = velocity of impact
S = the crush distance of the vehicle
Using Galileo’s mathematical formula, Robbins cites two examples:
Example #1 Example #2
Velocity (V) 12 m/s 12 m/s
Crush Distance (s) 1 meter (m) .2 meter (m)
Acceleration (a) V² / 2s V² / 2s
Acceleration (a) 12² / (2) X (1) 12² / (2) X (.2)
Acceleration (a) 144 / 2 144 / .4
Acceleration (a) 72 m/s² 360 m/s²
Acceleration (a) 72 m/s² / 9.81 m/s² 360 m/s² / 9.81 m/s²
Acceleration (a) 7Gs 73.4 Gs

Neck Pain Whiplash
Look at the numbers carefully. In the second example, for the same velocity,
crushing the vehicle 80% less (1 meter versus .2 meters) resulted in significant more
vehicle acceleration (5 times more [7 Gs v. 36 Gs]). The results show that the greater the
crush damage distance of the vehicle, the less the G force received by the occupant. Or,
the smaller the crush damage distance of the vehicle, the greater the G force received by
the occupant, which is associated with greater acceleration inertial injury.
The use of stiff motor vehicle bodies and chassis, when subjected to relatively
severe impacts, may result in little or no damage to the vehicle body or bumper, yet the
occupants are subjected to high G force, resulting in whiplash injury. Robbins states:
“….crush damage does not relate to the expected occupant injury, i.e.,
the more vehicle damage, the more change that the occupant is
injured, is not a conclusion that can be made. In fact, it is more likely
the opposite.
Doctors are missing the boat. Despite the fact that many doctors remembers
George’s Line, I have found that most still do not understand its true significance. In
personal-injury cases, it is the most important test a chiropractor or medical doctors can
do when examining the patient with neck pain.
Doctors that evaluate auto-accident patients are performing great disservice if they
are not analyzing George’s Line. Crash victims who walk into medical or chiropractic
offices with breaks in George’s Line generally do not have simple sprains/strains or
neural arch fractures. Approximately 35 percent to 45 percent of car-accident
patients have something in between, namely ligament partial rupture with
clinical instability that manifests as a break in George’s Line on the flexion
and extension films.

Neck Pain Whiplash
The AMA’s Guides to the Evaluation of Permanent Impairments uses George’s Line
to rate neck impairments. Most medical doctors see small anterolisthesis and/or
retrolisthesis on the films and ignore it or fail to appreciate its significance. This can be
the difference between policy limits and not.
In 1919, A. George published “A Method for More Accurate Study of Injuries to the
Atlas and Axis” in the Boston Medical and Surgery Journal, which was renamed The
New England Journal of Medicine in 1928. He described his method of drawing a line
on the posterior cervical vertebral bodies and looking for the key landmark, which is the
alignment of the superior and inferior posterior body corners. In 1987, Yochum and
Rowe published Essentials of Skeletal Radiology and described the significance of
George’s Line. “If an anterolisthesis or retrolisthesis is present, then this may
be a radiologic sign of instability due to … ligamentous laxity.” As a peer
review provider I have seen thousands of reports and have only seen ligamentous laxity
a few dozen times. Many of you have read these terms but if the correct diagnoses are
not made the value of the case drops significantly.
Total translation of greater than 3.5 mm in the cervical spine is a DRE
Category IV permanent impairment of 25 percent to 28 percent whole
person in the AMA Guides. This is the same percentage of impairment for a
patient who has had spine surgery to fuse two vertebrae. The physiological
result of this excessive movement is that the body tries to stabilize the injured joint by
splinting the muscles to guard the injured joint. These chronic muscle spasms continue
for several years until degenerative arthritis can stabilize the joint. The neck joints with
partial ligament ruptures will develop DJD within a few years (visible on
radiographs within seven years).
These patients are the ones who never heal. After the first six months of treatment
following the car accident, unfortunately, the patient is then right back where they
started with excessive vertebra motion.
Whiplash injury is an inertial mechanical injury – the spine to be exposed to a high
degrees of compression, shearing, tension and rotational forces in a rapid sequence,
which was virtually instantaneous. It is the timing or the lack of time for the body to
react to these forces that cause the injury anatomically and scientifically.
Example: Let’s assume your patient/ client was struck from the rear. The
mechanism would occur to the cervical spine. The force of the impact exposes the discs,
facet joints and the ligaments to significant stress. Image A. Normal anatomy. Image
B. Is what occurs within .150 msec to .300msec of a rear impact crash.
Image A & B

Neck Pain Whiplash

Chiropractic spinal adjusting (manipulation) affects the facet joints. As
described by Canadian Orthopedic Surgeon and Professor, William
Kirkaldy-Willis, MD (9):
“Spinal manipulation is essentially an assisted passive motion applied to
the spinal apophyseal [facet] and sacroiliac joints.”
There are mechanical neurophysiological explanations as to how spinal
manipulation inhibits pain. The most accepted of these involve the use of the Gate
Theory by Ronald Melzack and Patrick Wall (10, 11), established more than 50 years
ago. This Gate Theory has survived the test of time (12). As described by R. KirkaldyWillis
(9):
Melzack and Wall proposed the Gate Theory of Pain in 1965, and this theory has
“withstood rigorous scientific scrutiny.”
As a consequence of the mechanical nature of their clinical practice, chiropractors
treat many whiplash-injured patients. Although chiropractors manage a wide range of
clinical syndromes and findings, the emphasis of chiropractic clinical practice is to treat,
primarily through spinal adjusting, regions of spinal hypomobility (less than normal
motion). However, chiropractors are well aware that spinal trauma may also cause
regions of hypermobility (excessive motion).
In the evaluation of an injured patient, chiropractors assess the spine for
both hypomobility and hypermobility.
Hypomobility is classically managed with spinal adjusting, myotherapy,
stretching exercises, and modalities that reduce spasm.
Hypermobility is classically managed by applying spinal adjusting to
adjacent hypomobile joints, varying forms of immobilization, and resistive effort
exercises.
Chiropractors are aware that trauma, especially whiplash trauma, can result in a risk
to the integrity of the nervous system. This type of hypermobility is referred to
as Clinical Instability. Clinical Instability management may require prolonged
immobilization, or on occasion a surgical stabilization. This paper reviews the historical
and contemporary perspectives on Clinical Instability