Over the last few years, a number of researchers have investigated the role of proprioception in the problem of whiplash. Some researchers have hypothesized that injury to the cervical facet joints may result in dysfunction of that part of the nervous system responsible for balance. (For a review of these studies, see our book Low Velocity Whiplash Biomechanics.)
A recent study again looked at this problem by studying the cervical movements, the cervical range of motion, and the oculomotor function of 27 whiplash patients. They compared these patients to 25 healthy control subjects, and found significant differences. They found that, "Repositioning dysfunction was present in 62% of subjects with whiplash trauma 2 years after the trauma." They also showed dysfunction in the oculomotor tests, indicating that "restriction of cervical movements and changes in the quality of proprioceptive information from the cervical spine region affect voluntary eye movements."
These dysfunctions could possibly result in dizziness or vertigo—a common symptom of whiplash injury—and also may indicate that if the proprioceptive function of the nerves in the facet joints are injured, the nociceptive—or pain carrying—nerves may also be involved as well. This could explain the chronic neck pain experienced by whiplash patients.
"Previous studies illustrate the presence of mechanoreceptive and nociceptive nerve endings in cervical facet capsules proving that these tissues are monitored by the central nervous system and implying that neural input from the facets is important to proprioception and pain sensation in the cervical spine. In our study significant correlations occurred between active range of cervical motion and oculomotor performances as well as kinesthetic sensibility, which could indicate that the zygapophysial joints' dysfunction mediates this proprioceptive dysfunction."
The authors conclude:
"These results point to a multifactorial background of the chronic morbidity after whiplash trauma. However, a proprioceptive dysfunction might be one of the most important factors for understanding the morbidity after a noncontact whiplash trauma to the neck."Heikkila HV, Wenngren BI. Cervicocephalic kinesthetic sensibility, active range of cervical motion, an oculomotor function in patients with whiplash injury. Archives of Physical Medicine and Rehabilitation 1998;79:1089-1094.