Objectives: Recent models of the relationship between posttraumatic stress and whiplash pain suggest that psychological stress relating to a motor vehicle crash may influence pain perception. The mechanisms of this relationship may be through more direct, psychological pathways, or through factors proposed by the fear-avoidance models of chronic pain. This study sought to investigate the relative contribution of fear-of-pain and trauma symptomatology to daily pain and time spent in an upright posture (uptime) in chronic whiplash-associated disorder (WAD).
Methods: Hourly electronic-diary reports were used to explore the within-day relationship of psychological trauma symptoms and fear-of-pain to same-hour and next-hour pain reports and next-hour uptime (measured by accelerometers) in 32 individuals with a chronic WAD. Within-person effects were analyzed for 329 diary entries using multilevel modeling with fixed slopes and random intercepts.
Results: Reports of trauma-related hyperarousal were associated with greater same-hour pain, and this relationship was mediated by fear-of-pain. Fear-of-pain and uptime were independently associated with reports of increased next-hour pain (controlling for first-order serial autocorrelation). Fear-of-pain was unrelated to next-hour uptime, but trauma-related avoidance symptoms were associated with reduced uptime. This study supports the relationship between psychological trauma responses and pain, suggesting behavioral (avoidance) pathways and effects on pain perception through fear-of-pain. These findings reinforce the need to evaluate traumatic stress as a factor in recovery from WAD.
*Division of Physiotherapy, CCRE: Spinal Injury, Pain and Health
†Centre for National Research on Disability and Rehabilitation Medicine (CONROD), The University of Queensland, Brisbane, Australia
Funding for this study was received from the Australian Research Council and The University of Queensland.
Reprints: Michele Sterling, PhD, Division of Physiotherapy, CCRE: Spinal Injury, Pain and Health, Centre for National Research on Disability and Rehabilitation Medicine (CONROD), The University of Queensland, Brisbane, Australia (e-mail: firstname.lastname@example.org).
Received for publication July 28, 2009; revised March 5, 2010; accepted March 7, 2010