There are several factors that affect the efficiency of the stabilization response to whiplash injury, including:
It should be known that some of these stabilization responses to whiplash are within the patient's capacity to control while others are not.
The posture in which a person is sitting at the moment of impact helps determine the efficiency of the stabilization response that will affect the severity of the whiplash injury.
Sitting in a correct posture promotes an efficient stabilization response.3 Sitting in a poor posture, particularly a "slumped" type posture, promotes an inefficient stabilization response.
The better conditioned the body is in general, the more efficient the stabilization response will be. This particularly relates to the condition of the nervous system, as a well-functioning nervous system is essential to a proper stabilization response.
Perhaps the most important factor that affects the efficacy of the stabilization response in relation to whiplash injuries is awareness of the impending impact.
Scenario 1: Aware of impending impact. This person is able to automatically prepare the stabilization system to respond quickly and efficiently.
Scenario 2: Unaware of the impending impact. This person cannot prepare the stabilization system, thus slowing the response and decreasing its efficiency. This person is likely to sustain greater whiplash injury than is the person who is aware.
This may help explain the findings of some studies that have shown a passenger in a struck vehicle is likely to sustain greater whiplash injury than the driver.4, 5 The driver is more likely to see the vehicle coming in the rear view mirror.
Women in general are more frequently and more seriously injured by whiplash than men due to the differences in muscular bulk and the female’s smaller bony structures. These factors result in less protection of the cervical spine to the abnormal forces such as those that occur in a whiplash-type of injury.
Risk factors influencing prognosis of a whiplash injury include:
A common misconception about whiplash injury is that if the vehicle does not sustain damage in a low speed impact, then whiplash injury to the occupant does not occur.
In reality, low impact collisions can produce correspondingly higher dynamic loading on the occupants because the lack of crushing metal to absorb the forces results in a greater force applied to items or occupants within the vehicle.7, 8
References
3. Murphy DR. "Normal function of the cervical spine II: Neurophysiology and stability." In: Murphy DR, ed. Conservative Management of Cervical Spine Syndromes. New York: McGraw-Hill, 1999:45-70.
4. Harder S; Veilleux M; Suissa S. "The effect of socio-demographic and crash-related factors on the prognosis of whiplash." J Clin Epidemiol 1998 May;51(5):377-84.
5. Parmar HV, Raymakers R. "Neck injuries from rear impact road traffic accidents: prognosis in persons seeking compensation." Injury 1993; 24:74-78.
6. Nordhoff L: "Motor Vehicle Collision Injury for the 1990's Doctor/Attorney", Automotive Injury Research Institute,1994.
7. Macnab I: "Acceleration Extension Injuries of the Cervical Spine." Rothman and Simeone, The Spine. 1982.
8. Hirsch SA, Hirsch PJ, Hiramoto H, "Whiplash Syndrome: Fact or Fiction?" Ortho C1 N Amer,19(4):791-95;1988.