Objective: To establish a structural equation model of lower back pain and its risk factors in occupational population in China based on a large-sample occupational epidemiological survey and structural equation analysis, so as to lay the foundation for the prevention of this disease. Methods: A total of 73497 occupational epidemiological cases were selected from June 2018 to December 2023 using the Chinese version of the Musculoskeletal Disorders Electronic Questionnaire. The results were analyzed using ergonomic hazard factors and their risk source classification criteria. Confirmatory factor analysis was then applied to extract individual factors, work organization, working postures, work types, muscle fatigue, and lower back pain. These factors were subsequently classified into six categories and structural equation model was established. Results: The main structural reliability and validity indexes of the structural equation model of lower back pain and its adverse ergonomic factors after adjustment were basically up to standard[goodness of fit index (GFI) was 0.956, the adjusted goodness of fit index (AGFI) was 0.944, the root mean square error of approximation (RMSEA) was 0.043, the normed fit index (NFI) was 0.922, the comparative fit index (CFI) was 0.923, and the Tucker-Lewis index (TLI) was 0.908], and the model fit was good. There were correlations among four exogenous latent variables: individual factors, work organization, working postures and work types. Among them, individual factors had a weak negative correlation with the three exogenous potential variables of work organization, working postures and work types (r=-0.30, -0.11, -0.18), and work organization had a moderate positive correlation with working postures and work types (r=0.49, 0.55). There was a strong positive correlation between work types and working postures (r=0.72). The direct path coefficients of individual factors, working postures and muscle fatigue were 0.07, 0.11 and 0.40, respectively. The direct path coefficients of work types were -0.07. There was an indirect path mediated by muscle fatigue between work types, working postures and work organization and lower back pain, and the indirect path coefficients were: work types-muscle fatigue-lower back pain (0.15), working postures-muscle fatigue-lower back pain (-0.04) and work organization-muscle fatigue-lower back pain (0.27) . Conclusion: When carrying out the prevention and control of lower back pain, the pathogenesis of lower back pain induced by workers' muscle fatigue caused by work organization, working postures, and work types factors should be comprehensively considered, so as to provide a theoretical reference for improving the prevention and control level of lower back pain.
目的： 基于大样本流行病学调查和结构方程分析方法，建立我国职业人群下背痛与各类危险因素的结构方程模型，为此类疾患的预防工作奠定基础。 方法： 筛选2018年6月至2023年12月使用《中文版肌肉骨骼疾患电子问卷》调查的73 497份全国职业流行病学个案数据。通过不良工效学因素及其来源分类标准和验证性因子分析分别提取下背痛相关的个体因素、工作组织、工作姿势、工作类型、肌肉疲劳和下背痛6个因子，对其进行结构方程分析，并建立结构方程模型。 结果： 调整后的下背痛及其不良工效学因素结构方程模型的主要结构信效度指标基本达标[拟合优度指数（goodness of fit index，GFI）为0.956，调整拟合优度指数（adjusted goodness of fit index，AGFI）为0.944，近似均方根误差（root mean square error of approximation，RMSEA）为0.043，规范拟合指数（normed fit index，NFI）为0.922，比较拟合指数（comparative fit index，CFI）为0.923，塔克-刘易斯指数（Tucker-Lewis index，TLI）为0.908]，模型拟合度较好。个体因素、工作组织、工作姿势和工作类型4个外生潜变量间具有相关性。其中，个体因素与工作组织、工作姿势、工作类型3个外生潜变量存在较弱的负相关（r=-0.30、-0.11、-0.18），工作组织与工作姿势、工作类型均存在中等程度的正相关（r=0.49、0.55），工作类型与工作姿势存在较强的正相关（r=0.72）。除工作组织外，其他外生潜变量与下背痛均存在直接路径，个体因素、工作姿势和肌肉疲劳的直接路径系数分别为0.07、0.11和0.40，工作类型的直接路径系数为-0.07；工作类型、工作姿势和工作组织与下背痛存在经肌肉疲劳中介的间接路径，其间接路径系数：工作类型-肌肉疲劳-下背痛（0.15）、工作姿势-肌肉疲劳-下背痛（-0.04）和工作组织-肌肉疲劳-下背痛（0.27）。 结论： 开展下背痛防控工作时，应综合考虑工作组织、工作姿势和工作类型因素导致劳动者肌肉疲劳进而诱发下背痛的发生路径，为提高此类疾患的防控水平提供理论参考。.
Keywords: Lower back pain; Musculoskeletal system; Risk factors; Structural equation model; Work-related musculoskeletal disorders.