People with chronic neck pain from whiplash injury can have changes in their balance. Scientists in Denmark used a special platform to look at changes in foot position as a measure of balance or loss of balance. The postural recordings are part of a study called posturography.
Posturography was compared for two groups. The first group had a chronic whiplash injury. The second (control) group had no neck pain and no history of whiplash injury. Active neck motion and position sense were measured for both groups.
Researchers applied vibration to the Achilles tendons of all subjects. Then muscles in the neck were injected with a salt solution. Subjects were asked to talk and to open and close their eyes while standing. Posture recordings were taken for both groups after each event.
People in the control group made all the needed postural adjustments. Being pushed off balance, closing their eyes, talking, or painful injections didn't prevent them from keeping their normal balance.
The researchers found decreased motion and reduced position sense in the whiplash group compared to the control group. The authors suggest these changes show a protective response in whiplash patients.
Postural control is altered after a whiplash injury. Damage to neck joints from the injury results in reduced position sense. There may be changes in the patient's vision. Postural responses are slowed down because visual responses are slower, so muscle activity is slower. We rely on position sense and our inner ear mechanism to keep an upright position and our balance.
Knowing about these differences in the postural system after whiplash may help us find ways to treat chronic symptoms. Posturography may help us find patients with these changes.