Whiplash disorder

6th September 2011 - Whiplash disorder

The definition of whiplash is any injury to the neck following a rapid movement of the head. Whiplash does not necessarily have to come following a motor accident.

Because the term whiplash does not describe the structure that has been injured, whiplash associated disorders can encompass a number of different conditions, making this quite a complicated topic.

Rapid movements of the head (weighing a hefty 5kg) can cause significant trauma to the cervical spine, from minor muscle strain to compression fractures and dislocations.

Most factors affecting the severity of whiplash disorders, for example speed and direction of impact, are out of our control. However, in the case of motor accidents, one crucial factor is headrest position.

Headrests first became mandatory in the United States in 1969, following the realisation that they significantly reduced the incidence of serious injuries and paralysis by limiting head movement.

They work by preventing your neck from going into hyper-extension and, in turn, reducing the degree of subsequent hyper-flexion, both of which can cause severe injury.

Hyper-extension phase

Fig. 1: Image showing extension of cervical spine during motor accident.

Adjusting your headrest so that it fits you is absolutely crucial to ensuring it does its job. If your headrest is out of position by just 2cm not only is it not working effectively, it may cause more damage than not having a headrest at all.

Setting up your headrest is very simple:

  1. Have the headrest as close to the back of your head as possible without it touching.
  2. The top of the headrest should be 2 to 3cm above the tops of your ears.
  3. Test the headrest by moving your head backwards. If you can extend your neck significantly then recheck your positioning.


Fig. 2: Image showing ideal headrest position.