Objectives The aim of this study was to examine the risk of carpal tunnel syndrome (CTS) among workers with daily occupational exposure to high-force and high-velocity manual work.

Methods The study was carried out retrospectively among a cohort of 1591 workers employed at a slaughterhouse or at a chemical factory; 1141 persons (71.7%) participated. Workers not doing tasks in slaughtering or meat processing constituted the reference group. Exposure assessments were made for 46 different tasks in slaughtering and meat processing from video-based observations at the workplace. CTS was diagnosed if there were current symptoms typical of CTS in combination with positive neurophysiological signs of CTS or if the subject had previously been operated on for CTS.

Results Altogether 1.6% of the reference group, 5.1% of the nondeboning slaughterhouse workers [prevalence ratio (PR) 3.23, 95% confidence interval (95% CI) 1.30-7.99] and 7.8% of the deboning slaughterhouse workers (PR 4.91, 95% CI 2.03-11.81) had CTS. Increased risk estimates persisted after adjustment for other potential risk factors by logistic regression. The prevalence of CTS in the dominant hand was equally increased in both groups of slaughterhouse workers (but only statistically significant for the workers in deboning tasks), while the prevalence of CTS in the nondominant hand was significantly increased only among the slaughterhouse workers in deboning tasks.

Conclusion This study supports the hypothesis that daily high-velocity and high-force manual work is a risk factor for CTS.

Key terms carpal tunnel release; hand intensive work; historical cohort; neurophysiology