Dizziness and Balance Problems After Auto Injury
The neck plays an important role in not only the support and movement of the head, but also plays a critical role in maintaining balance and posture. Studies have demonstrated that severe neck pain can compromise the ability of the neck to stabilize head movements and can contribute to balance problems. What has been uncertain from prior research is whether auto injury trauma in particular may have an effect on head steadiness distinct from the effects of non-traumatic neck pain.
A 2010 study sought to investigate whether differences exist in head steadiness between patients after a car crash and those with chronic non-traumatic neck pain. Researchers assessed head steadiness in 173 participants, who each represented one of three groups:
- 59 patients with auto injury disorders, grades I-II, persisting longer than six months and less than 10 years;
- 57 patients with chronic non-traumatic neck pain, persisting longer than 6 months and less than 10 years; and
- 57 healthy volunteers to serve as a controls.
Exclusion criteria for the car crash group consisted of a diagnosis of WAD grades III-IV, a history of similar symptoms prior to the accident, head injury during the accident, surgery of the cervical spine, or any symptom-related systemic disease. Subjects were excluded from the chronic neck pain group if they had any history of neck trauma or known systemic disease related to the symptoms. The control group had no previous or current history of neck pain or neck trauma, and excluded pregnant women and people unable to participate in an MRI.
Testing required participants to lay in two positions for each of the measured tasks. In the low load task, participants leaned backwards at a 60 degree angle, with full head support to allow a neutral resting position. Subjects were asked to lift their heads one centimeter from the headrest and hold completely still for 40 seconds, as a researcher timed the task. A 3Space Fastrak transmitter was placed above the head, to measure the orientation and position of the head in three dimensions. The 3Space Fastrak has been found, in previous studies, to be reliable in recording positioning among both neck pain patients and healthy subjects. The high load task consisted of the same test, with subjects lying in a supine position. Subjects who were unable to hold their heads for at least 10 seconds were excluded from the study.
In addition to the system measurements, researchers also measured subjects' subjective assessments of pain and dizziness. Participants in each group rated the intensity of any neck pain they experienced during the testing on a scale of 0-10, and levels of dizziness on a scale of 1-5. The results showed significant differences between the whiplash patients and both the chronic neck pain patients and the healthy controls. Researchers wrote: "The whiplash group showed significantly decreased head steadiness in the low load task compared with the other two groups. The difference was explained largely by severe levels of neck pain and dizziness."
Healthy volunteers were not expected to show fatigue in the testing, and the results confirmed that steadiness gradually increased for control subjects throughout the low load task. Among the WAD subjects, in contrast, unsteadiness persisted throughout the testing, and in fact, the whiplash group was far less able to maintain head steadiness than the other two groups.
The inclusion criteria ensured that the two pain groups differed only by the history of trauma. Yet the differences in performance on the low load task and levels of neck pain and dizziness while performing that task was significant. This study suggests that whiplash patients suffer from reduced head steadiness related to their history of trauma.
Because balance issues can complicate recovery, it's important to identify these problems early on so that proper treatment can help prevent long-term complications.
Woodhouse A, Liljebck P, Vasseljen O. Reduced Head Steadiness in Whiplash Compared with Non-traumatic Neck Pain. Journal of Rehabilitative Medicine 2010;42:69-75.