A review and methodologic critique of the literature supporting 'chronic whiplash injury': part I - research articles.

The existence of a 'chronic whiplash injury' has been a source of debate in the medical literature for many years. Some authors have published articles suggesting that chronic whiplash syndrome is the result of chronic pathology (injury), and that this injury may occur at any collision speed; others have stated that any psychological factors are secondary rather than primary (etiologic) to the problem of chronic pain, or that secondary gain is a rare or uncommon phenomenon. These articles contradict scientific measures and efforts which show that for Quebec Task Force Grade 1 and 2 whiplash-associated disorders, the highly prevalent problem of chronic pain may be a culturally and psychosocially determined phenomenon, in which confounding psychosocial variables determine the behaviour and outcome following an otherwise benign acute injury. The authors of the current literature critique reviewed the biomedical and engineering literature relating to whiplash syndrome, searching for articles that supported the construct of 'chronic whiplash injuries'. Thirty seven articles containing fourteen distinct statements supporting the construct of 'chronic whiplash injuries' were found that fit the inclusion criteria. The methodology described in these articles was evaluated critically to determine if the authors' conclusions regarding 'chronic whiplash injuries' were scientifically sound. The authors of the current critique found that all of the articles contained significant methodologic errors relative to their respective authors' statements regarding chronic whiplash. The most frequent concerns reside with sampling, experimental design and interpretation of data.