Factors affecting the whiplash injury

There are several factors that affect the efficiency of the stabilization response during whiplash, some of which are within our capacity to control, others of which are not. These include:

1. Posture at impact
2. Overall physical condition
3. Awareness of coming impact
4. Gender
5. Others

How posture at impact affects a whiplash injury
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.

How overall physical condition affects a whiplash injury
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.

How awareness of coming impact affects a whiplash injury
Perhaps the most important factor that affects the efficacy of the stabilization response in relation to whiplash 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(4, 5) that have shown a passenger in a struck vehicle is likely to sustain greater whiplash injury than the driver. The driver is more likely to see the vehicle coming in the rear view mirror.

How gender affects a whiplash injury
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.

How other factors affect a whiplash injury
Risk factors influencing prognosis of a whiplash injury(6):

• Symptoms persisting beyond 6 months. (43% failed to recover on average)
• Significant ligament, disc, nerve, or joint capsule injury.
• Delay in initiating treatment
• Need to resume treatment for more than one flare-up of pain.
• Occupant age over 65
• Head restraint more than 2" away from occupant's head.
• Occupant in a small car
• Alcohol intoxication at time of automobile accident
• Pre-existing x-ray evidence of degenerative changes
• Prior whiplash injury
• Prior cervical spine fusion
• Patient having initial radicular (arm pain, numbness, tingling) symptoms
• A cervical collar used for more than 2 weeks

Common misconception about whiplash injury
A common misperception 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, however, 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).

By: Donald Murphy, DC
August 17, 2000