ABSTRACT
BACKGROUND: The use of snap-fit fasteners in automotive assembly has increased in the last 10 years. Their impact on musculoskeletal function of the upper limbs in assembly workers is not well described. AIMS: To investigate the association between snap-fit assembly and upper limb functional limitations (ULFLs) in workers after a large-scale expansion of snap-fit assembly by a German automotive company. METHODS: Cross-sectional data on blue-collar production workers' exposure to snap-fit assembly and ULFLs were collected from medical check-ups and company registers. The association between duration of snap-fit assembly and ULFLs, and the dose-response relationship between the two were analysed using logistic regression, adjusted for body mass index, gender and employment duration before snap-fit exposure. RESULTS: The study group included 10722 workers. Within the company, 8.4, 6.9 and 10.3% were exposed to snap-fit 1-12, 13-24 and ≥25 months, respectively. After adjusting for confounders, snap-fit exposure for 1-12 months [odds ratio (OR) = 1.59, 95% confidence interval (CI) 0.88-2.88] and 13-24 months (OR = 1.48, 95% CI 0.76-2.88) was not statistically significantly associated with ULFLs compared with an unexposed group. However, exposure to ≥25 months of snap-fit assembly was statistically significant associated with ULFLs showing >2-fold risk (OR = 2.44, 95% CI 1.52-3.92). No clear dose-response relationship was found. CONCLUSIONS: Our study suggests a negative long-term impact from snap-fit assembly on workers' upper limb function. Company physicians should be vigilant for signs of upper limb musculoskeletal disorders among workers exposed to snap-fit assembly.
