Background Musculoskeletal disorders (MSDs), a common type of occupational diseases, have become the main cause of absenteeism and early retirement in the occupational population, as well as a major risk factor for occupational disability. The purpose of this study was to investigate the effects of occupational stress and mental health on MSDs in coal miners in Xinjiang, China, to provide a theoretical basis for reducing the incidence of MSDs in coal miners and improving their physical and mental health. Methods In this study, stratified cluster random sampling was used to randomly select six coal mining companies in Xinjiang, and 1675 coal miners were surveyed by questionnaire. The status of occupational stress, mental health and MSDs among coal miners was investigated by means of the Effort–Reward Imbalance questionnaire (ERI), Symptom Checklist-90(SCL-90), and Musculoskeletal disorders scale (MSDs) questionnaire. Results The prevalence of MSDs among coal miners was higher, and there were statistical differences among different sexes, ages, working years, shifts, types of work, educational level and monthly income (P < 0.001). The prevalence of MSDs in different body parts in the occupational stress group and mental disorder group was higher than that in the normal group. The results of multivariate logistic regression analysis showed that females had an increased risk of developing MSDs (OR = 2.23, 95% CI.:1.50,3.33). The risk of MSDs was higher with age < 30 years (30-39 years,OR = 2.39, 95% CI.,1.68,3.40; 40-49 years,OR = 2.15, 95% CI.:1.52,3.04; 50-60 years:OR = 3.25, 95% CI.:2.09,5.07), and the longer the working years, the higher the risk of MSDs (OR = 1.90, 95% CI.:1.38,2.62). The two shifts group (OR = 2.18, 95% CI.:1.59,2.98) had an increased risk of developing MSDs compared with the fixed day shift group. The risk of MSDs was lower in heading drivers (OR = 0.41, 95% CI.:0.29,0.60,) and transport workers (OR = 0.30, 95% CI.:0.20,0.43). The higher the education level, the lower the risk of MSDs (high school: OR = 0.46, 95% CI.:0.34,0.62, junior college and above: OR = 0.12, 95% CI.:0.08,0.17), and the higher the monthly income, the lower the risk of MSDs (OR = 0.50, 95% CI.:0.34,0.74). Occupational stress (OR = 1.32, 95% CI.:1.05,1.67) and mental disorder(OR = 2.94, 95% CI.:2.25,3.84) increased the risk of MSDs. A Bayesian network diagram showed that occupational stress and MSDs have direct effects on mental disorders, and occupational stress can have indirect effects on mental disorders through MSDs. Conclusion Our research shows that MSDs are common among coal miners. Occupational stress and psychological disorders can increase the incidence of MSDs.

Background: Coal is the core energy source of the global energy system. To ensure the sustainable development of the coal industry, the mental health of coal miners is crucial. Methods: This cross-sectional study was conducted between August 2018 and June 2019. A total of 1,675 coal miners were surveyed using the Musculoskeletal Disorders (MSDs) Questionnaire and the Symptom Checklist-90 (SCL-90). At the same time, polymorphisms in the BDNF gene (rs6265, rs10835210) and TPH2 gene (rs4570625, rs4131347) in whole blood DNA were detected to analyze the influence of a gene-environment interaction on mental health. Results: The results showed that the mental health status of coal miners was poorer than the Chinese norm (P < 0.05). The mental health status of workers with MSDs was lower; MSDs interact with the BDNF gene rs6265 and TPH2 gene rs4570625, which affects mental health. Conclusions: It is suggested that employers should improve the working environment of workers, shorten the working time, pay attention to the mental health of workers, and provide timely psychological counseling to workers who suffer from mental health problems, so as to improve workers’ mental health and working ability, as well as their quality of life.