Recent research reported in The Spine Journal compared anatomical differences in the neck and trunk area of young adult patients with chronic neck pain and control subjects without neck pain to identify risk factors and predictors. The study found that a shallow rib cage in women and forward inclination of the thoracic inlet in men are associated with the development of chronic neck pain. The researchers concluded that individuals with these potential risk factors “might benefit from preventive measures, such as postural adaptation or ergonomic support, to lessen the chance of the development of weak points in daily life or strengthen the muscles holding the structures so as to eliminate fatigue.”
We asked PAINWeek faculty member James Matthew Elliott, PT, PhD, for some additional insights into the etiology of chronic neck pain. As director of the Neuromuscular Imaging Research Lab at Northwestern University’s Feinberg School of Medicine, Dr. Elliott has been extensively involved in the study of the transition to chronic neck pain, particularly as related to traumatic injury such as whiplash.
With respect to anatomical risk factors for chronic neck pain, would you comment further on what these might include?
At this point, the imaging generally doesn’t tell us all that much with respect to patho-anatomical risk factors, except to rule out red-flags. These could include, but are not limited to: Drop attacks, dizziness, reduced ROM, UE/LE pain. It is also important to rule out Fx, dislocation, or anything more sinister. Guidelines strongly suggest clinicians continue to work with and follow the Canadian Cervical Spine Rules (CCR) or NEXUS with regard to need for radiography.
What additional research avenues might be useful to pursue, to refine our understanding of the predisposition to chronic neck pain, and to develop better preventative and interventional treatments in the clinical setting?
There have been remarkable breakthroughs in understanding the biology and physiology of pain and neural plasticity of the nervous system. But are there other important factors involved in the prediction of the clinical course of neck pain? It is clear that the mechanisms underlying poor functional recovery are very complex. It is also important to consider looking at relationships between neurobiology and psychosocial factors in an integrated fashion.
With respect specifically to whiplash, a special issue appeared in the journal Spine in December 2011. It represents the most up to date review of whiplash and its associated disorders. The 2011 special issue was the culmination of the international whiplash symposium in Brisbane, Australia- February 2011. A 2nd International research symposium, sponsored by the International Association for the Study of Pain (IASP) took place in Aarhus, Denmark in March of 2014. Plans are underway for a 3rd conference to convene in 2016, location to be determined.
What is our current understanding of the connection between traumatic injury—such as whiplash—and the development of chronic pain?
Whiplash from a motor vehicle collision (MVC) is very different from idiopathic, non-traumatic neck pain. Patients with non-traumatic neck disorders often present with lower levels of pain-related disability. While 50% of those involved in a MVC can expect full-recovery within the first 2-3 months, a significant proportion (25-50%) of patients present with signs of central nervous system hyperexcitability and other psychological factors such as Posttraumatic Stress Disorder (PTSD). Some of these factors have shown to consistently influence and define the clinical course in the long term.
Accordingly, research has continued to focus on identifying a set or sets of predictors – 1) moderate levels of PTSD, 2) presence of cold hypersensitivity, 3) older age (over 35), 4) female, 5) higher initial levels of pain-related disability, 6) reduced neck ROM, and 7) some preliminary evidence from MRI based studies investigating muscle degeneration. In support of a biopsychosocial framework of clinical practice, it’s important for clinicians to consider these factors in their acute clinical decision making, as their presence predicts clinical pathways.
What are some of the present unknowns with respect to this understanding that would benefit from further research and study?
Idiopathic/non-traumatic neck pain seems to be a bit more straightforward compared to traumatic whiplash and those patients with idiopathic neck pain seem to respond more favorably to straightforward evidenced based rehabilitation interventions, such as manual therapy and exercise. Recent evidence from three different trials, however, does not support this for acute or chronic whiplash (Michaleff et al., 2014 – The Lancet; Lamb et al., 2013 – The Lancet; Jull et al., 2013, Pain). It is imperative that studies now work towards developing and establishing better interventions for patients with traumatic neck pain. To do so, we must improve our understanding of the mechanisms underlying poor functional recovery. This is well underway in various labs around the world.