Work relatedness of chronic neck pain with physical findings--a systematic review

OBJECTIVES: This paper systematically reviews the work-relatedness of neck-shoulder disorders with associated physical findings. METHODS: Studies incorporating a physical examination were focused upon. Four detailed reviews were searched, and a systematic search of the MEDLINE, Embase BIDS, and Psychinfo databases was conducted until May 2006, the key words for the outcome and various occupational exposures being combined. The quality of each paper was rated by criteria related to study design, power, sampling methods, response rate, potential for bias, or confounding, and approaches to the assessment of exposure outcome. Weight was given to studies with objective exposure-response information. RESULTS: Twenty-one relevant reports (four prospective) were found. Most considered the outcome neck pain with palpation tenderness (tension neck syndrome) or mixed neck-shoulder disorder (predominantly tension neck syndrome). Most investigations shared common limitations--small sample size, potential for confounding, incomplete blinding, and crude exposure assessment. The overall quality of the information was rated as excellent for only two reports. Exposures included repetitive work (14 studies), static loading (12 studies), neck flexion (7 studies), force (5 studies), and occupational psychosocial factors (7 studies). Moderate evidence was found for a causal relation for repetition at the shoulder and for neck flexion allied with repetition. Limited evidence was found for hand-wrist repetition, neck flexion with respect to static loading and force in the absence of repetition, and high job demands, low control, low job support and job strain. CONCLUSION: There is some evidence that neck pain with palpation tenderness is causally related to workplace exposures. However, evidence is lacking on the validity, clinical course, and functional importance of this diagnostic entity.