Pressure pain thresholds in office workers with chronic neck pain. A systematic review and meta-analysis.

OBJECTIVES 1) Compare pressure pain threshold (PPT) values between office workers with chronic neck pain and asymptomatic controls; 2) establish reference PPT values in chronic neck pain; 3) evaluate associations between PPTs, pain intensity and disability. METHODS Seven English/Portuguese databases were searched for relevant literature. Studies investigating adult office workers (age >18) with chronic neck pain were included if PPTs were an outcome. The risk of bias was assessed using the Downs and Black checklist. Meta-analysis was conducted if a cluster contained at least two studies reporting the same PPTs. RESULTS Ten high quality, two low quality, and one poor quality studies were included. The meta-analysis revealed decreased PPT values in the upper trapezius, extensor carpi ulnaris, and tibialis anterior in chronic neck pain workers when compared with healthy workers, without a statistical difference (p>0.05). The PPT reference value in the upper trapezius was 263 kPa (95%CI: 236.35, 289.70), and 365 kPa (95%CI: 316.66, 415.12) for the tibialis anterior in office workers with chronic neck pain. No correlations were found between the upper trapezius PPT and pain intensity and disability. CONCLUSION This meta-analysis found that all the pressure pain threshold measurements were not significantly reduced in office workers with chronic neck pain compared with healthy workers. These assumptions were based on a small sample of existing studies, and therefore further studies are necessary to quantify the differences in pressure pain thresholds. Hypersensitivity PPT reference values are proposed for localized and extra-segmental sites in office workers with chronic neck pain.