1.Multimodal ultrasound of the testis in differentiating subtypes of spermatogenic dysfunction:a preliminary study
Tingting LEI ; Gaoxiang FAN ; Penglin ZOU ; Chao JIA ; Hongmei LIANG ; Jun LIN ; Rong WU ; Lianfang DU ; Zheng LI ; Qiusheng SHI
Chinese Journal of Ultrasonography 2025;34(8):678-685
Objective:To analyze the imaging features of testicular conventional ultrasonography(US),shear wave elastography(SWE),and contrast-enhanced ultrasonography(CEUS)in subtypes of spermatogenic dysfunction(focal,arrest,and exhausted),and to evaluate the diagnostic efficacy of testicular multimodal ultrasound.Methods:A prospective study enrolled 310 spermatogenic dysfunction patients(focal type group: n=77,arrest type group: n=20,exhaustive type group: n=213)and 30 healthy volunteers(control group)at Shanghai General Hospital between October 2023 and December 2024. All patients underwent preoperative testicular US,SWE,and CEUS examinations,followed by microdissection testicular sperm extraction. Ultrasound parameters were compared among groups,and receiver operating characteristic(ROC)curves were plotted to assess the diagnostic efficacy of multimodal ultrasound for different subtypes. Results:①Testicular volume:The arrest group exhibited significantly greater volume compared to the focal group and the exhausted group(all P<0.05). No statistically significant difference was observed between the arrest group and the normal group( P>0.05). ②Mean Young's modulus(Emean):The arrest group exhibited significantly lower Emean compared with both the focal and exhausted groups(all P<0.05),but showed no significant difference versus the normal group( P>0.05). ③CEUS quantitative parameters:The arrival time(AT)and time to peak(TTP)in the exhausted group were higher than those in the normal group,while the peak intensity(PI)and area under the time-intensity curve(AUC)were lower(all P<0.05). No significant differences were found in AT,TTP,or AUC among the three spermatogenic dysfunction subgroups(all P>0.05). ④CEUS perfusion patterns:The focal group predominantly exhibited a mottled pattern(70.13%,54/77). Both the arrest group(90.00%,18/20)and the normal group(93.33%,28/30)predominantly exhibited an rich pattern. The exhausted group predominantly exhibited a sparse pattern(56.34%,120/213). ⑤ROC curve analysis showed that for differentiating the arrest group from the focal type group and the exhaustive type group,the combination of Emean,testicular volume,and CEUS perfusion pattern yielded an AUC of 0.931,with a sensitivity of 95.00% and specificity of 85.86%. For differentiating the focal type group from the exhaustive type group,the combination of testicular echogenicity,CEUS perfusion pattern,and Emean yielded an AUC of 0.833,with a sensitivity of 81.82% and specificity of 75.12%. Conclusions:Multimodal ultrasonography can comprehensively characterize the imaging features of different subtypes of spermatogenic dysfunction,holding promise as a noninvasive predictive tool.
2.Simultaneous Determination of Nine Trace Organic Amines and Six Trace Inorganic Cations in Atmospheric Fine Particulate Matter by Ion Chromatography
Jing-Jia SHI ; Zhao-Qing CAI ; Jia CHEN ; Hui-Jun ZOU ; Tian TIAN ; Zheng WANG
Chinese Journal of Analytical Chemistry 2025;53(1):124-132
An ion chromatography method was developed for detection of nine kinds of trace organic amines(Methylamine,dimethylamine,trimethylamine,ethylamine,diethylamine,triethylamine,n-propylamine,n-butylamine,and ethanolamine)and six kinds of trace water-soluble inorganic cations(Li+,Na+,NH4+,K+,Ca2+,and Mg2+)in atmospheric fine particulate matter(PM2.5)in this wok.Various chromatographic columns(IonPac CS12,IonPac CS17 and IonPac CS19)were compared in terms of their separation efficiency for target analytes,and IonPac CS19 column was ultimately selected.Through meticulous optimization of the column temperature,a low temperature condition of 20℃was found to achieve the highest separation efficiency(All are above 1),effectively separating all 15 kinds of target analytes.Under the optimal analytical conditions inculding methanesulfonic acid(MSA)as eluent,100 μL of injection volume,column temperature at 20℃and eluent at flow rate of 1 mL/min,the detection limits of this method ranged from 0.05 to 7.15 μg/L,the quantification limits were 0.16-23.82 μg/L,and the spiking recoveries were 84%-105%.The proposed method exhibited high accuracy and excellent reproducibility,and was suitable for concurrent analysis and measurement of organic amines and water-soluble inorganic cations in PM2.5.
3.Mechanism of Chaijin Jieyu Anshen Formula in regulating synaptic damage in nucleus accumbens neurons of rats with insomnia complicated with depression through TREM2/C1q axis.
Ying-Juan TANG ; Jia-Cheng DAI ; Song YANG ; Xiao-Shi YU ; Yao ZHANG ; Hai-Long SU ; Zhi-Yuan LIU ; Zi-Xuan XIANG ; Jun-Cheng LIU ; Hai-Xia HE ; Jian LIU ; Yuan-Shan HAN ; Yu-Hong WANG ; Man-Shu ZOU
China Journal of Chinese Materia Medica 2025;50(16):4538-4545
This study aims to investigate the effect of Chaijin Jieyu Anshen Formula on the neuroinflammation of rats with insomnia complicated with depression through the regulation of triggering receptor expressed on myeloid cells 2(TREM2)/complement protein C1q signaling pathway. Rats were randomly divided into a normal group, a model group, a positive drug group, as well as a high, medium, and low-dose groups of Chaijin Jieyu Anshen Formula, with 10 rats in each group. Except for the normal group, the other groups were injected with p-chlorophenylalanine and exposed to chronic unpredictable mild stress to establish the rat model of insomnia complicated with depression. The sucrose preference experiment, open field experiment, and water maze test were performed to evaluate the depression in rats. Enzyme-linked immunosorbent assay was employed to detect serum 5-hydroxytryptamine(5-HT), dopamine(DA), and norepinephrine(NE) levels. Hematoxylin and eosin staining and Nissl staining were used to observe the damage in nucleus accumbens neurons. Western blot and immunofluorescence were performed to detect TREM2, C1q, postsynaptic density 95(PSD-95), and synaptophysin 1(SYN1) expressions in rat nucleus accumbens, respectively. Golgi-Cox staining was utilized to observe the synaptic spine density of nucleus accumbens neurons. The results show that, compared with the model group, Chaijin Jieyu Anshen Formula can significantly increase the sucrose preference as well as the distance and number of voluntary activities, shorten the immobility time in forced swimming test and the successful incubation period of positioning navigation, and prolong the stay time of space exploration in the target quadrant test. The serum 5-HT, DA, and NE contents in the model group are significantly lower than those in the normal group, with the above contents significantly increased after the intervention of Chaijin Jieyu Anshen Formula. In addition, Chaijin Jieyu Anshen Formula can alleviate pathological damages such as swelling and loose arrangement of tissue cells in the nucleus accumbens, while increasing the Nissl body numbers. Chaijin Jieyu Anshen Formula can improve synaptic damage in the nucleus accumbens and increase the synaptic spine density. Compared to the normal group, the expression of C1q protein was significantly higher in the model group, while the expression of TREM2 protein was significantly lower. Compared to the model group, the intervention with Chaijin Jieyu Anshen Formula significantly downregulated the expression of C1q protein and significantly upregulated the expression of TREM2. Compared with the model group, the PSD-95 and SYN1 fluorescence intensity is significantly increased in the groups receiving different doses of Chaijin Jieyu Anshen Formula. In summary, Chaijin Jieyu Anshen Formula can reduce the C1q protein expression, relieve the TREM2 inhibition, and promote the synapse-related proteins PSD-95 and SNY1 expression. Chaijin Jieyu Anshen Formula improves synaptic injury of the nucleus accumbens neurons, thereby treating insomnia complicated with depression.
Animals
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Male
;
Rats
;
Nucleus Accumbens/metabolism*
;
Drugs, Chinese Herbal/administration & dosage*
;
Depression/complications*
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Membrane Glycoproteins/genetics*
;
Rats, Sprague-Dawley
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Sleep Initiation and Maintenance Disorders/complications*
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Neurons/metabolism*
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Receptors, Immunologic/genetics*
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Signal Transduction/drug effects*
;
Synapses/metabolism*
4.Structural equation analysis of the incidence of shoulder WMSDs and individual and work-related factors
Shuang ZHOU ; Zhongxu WANG ; Ruijie LING ; Qing XU ; Huadong ZHANG ; Yimin LIU ; Gang LI ; Yan YIN ; Hua SHAO ; Jue LI ; Hengdong ZHANG ; Bing QIU ; Dayu WANG ; Qiang ZENG ; Yan YE ; Bin XIAO ; Hua ZOU ; Jianchao CHEN ; Dongxia LI ; Yongquan LIU ; Jixiang LIU ; Enfei JIANG ; Jun QI ; Liangying MEI ; Xianfeng ZHAO ; Mimi YANG ; Ning JIA
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(2):91-100
Objective:To investigate the incidence of shoulder work-related musculoskeletal disorders (WMSDs) among occupational population in China, and to explore their intrinsic association with personal and work-related factors.Methods:In April 2024, 73497 valid questionnaires of the Chinese version of the Musculoskeletal Disorders Electronic Questionnaire were retrospectively analyzed from June 2018 to December 2023 in 22 provinces and 29 key industries in China, and the general information, occurrence of WMSDs and related risk factors of key occupational populations in different regions in China were collected. By using Chi-square test and confirmatory factor analysis, the relationship between shoulder fatigue and pain in key occupational groups and individual factors, work type, work posture and work organization was discussed, and the internal relationship was analyzed based on structural equation model.Results:Higher incidence of shoulder fatigue and pain were associated with female, lack of physical exercise, uncomfortable working posture and neck leaning forward ( P<0.05). Structural equation model analysis showed that work type, work posture and work organization were strongly correlated ( r=0.58, 0.55). Work organization and work type were strongly correlated with shoulder fatigue ( r=0.65) and moderately correlated with shoulder fatigue ( r=0.21). Shoulder fatigue was moderately associated with shoulder pain ( r=0.40). Individual factors, work type, work posture and shoulder fatigue could directly affect shoulder pain ( OR=0.07, -0.09, 0.17 and 0.40), and work type and work posture could also indirectly affect shoulder pain through shoulder fatigue ( OR=0.08, 0.03). Work organization only indirectly affected shoulder pain through shoulder fatigue ( OR=0.26) . Conclusion:The main influencing factor of shoulder pain is shoulder fatigue, followed by work posture and individual factors. Structural equation model can better reflect the complex relationship between work type, work posture and work organization and shoulder WMSDs. Improving work posture and work organization may be an effective way to control the influence of shoulder fatigue on shoulder pain.
5.Structural equation analysis and modeling of fect and ankles WMSDs and its adverse ergonomic factors
Xi ZHANG ; Ning JIA ; Xin SUN ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Gang LI ; Yan YIN ; Hua SHAO ; Hengdong ZHANG ; Yanmin QI ; Bing QIU ; Tiebing LIU ; Dayu WANG ; Qiang ZENG ; Yan YE ; Bin XIAO ; Hua ZOU ; Jianchao CHEN ; Dongxia LI ; Yongquan LIU ; Jixiang LIU ; Enfei JIANG ; Jun QI ; Liangying MEI ; Tianlai LI ; Mimi YANG ; Xinwei GUO ; Zhongxu WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(2):101-109
Objective:To explore the structural equation model to explore the levels of work-related musculoskeletal disorders (WMSDs) and various risk factors in the feet and ankle of China's occupational population, providing scientific basis for for preventing WMSDs in feet and ankles.Methods:Data of 73497 national occupational epidemiological cases were selected from June 2018 to December 2023 used the Chinese version of the Electronic Questionnaire on Musculoskeletal Disorders. The adverse ergonomic factors and their source classification standard and confirmatory factor analysis were used to investigate foot and ankle WMSDs and their related risk factors (including individual factors, work organization, work posture, work type, fatigue, etc.) in key occupational groups in China, and structural equation model hypothesis, fitting, verification, and path and intermediary effect analysis were carried out. The model fit evaluation indexes included Chi-square specific degrees of freedom ( χ2/ df), gauge fit index (NFI), Tucker Lewis index (TLI), goodness of Fit index (GFI), adjusted Goodness of Fit index (AGFI) and approximate root mean square error (RMSEA) . Results:A total of 73497 occupational workers were surveyed, with local muscle fatigue and WMSDs incidence rates in the feet and ankles being 17.17% and 12.06%, respectively. The fitting index of the adjusted structural equation model basically meets the standard (GFI=1, AGFI=1, RMESA=0.042, NFI=0.716, TLI=0.663). The top three factors affecting feet and ankle WMSDs are feet and ankle muscle fatigue, work type, and work organization, with standardized path coefficients of 0.221, 0.105, and 0.095, respectively. The top two factors affecting feet and ankle muscle fatigue are work organization and work type, with standardized path coefficients of 0.548 and 0.383, respectively. Feet and ankle muscle fatigue, work type, work organization, and work posture have a direct effect on feet and ankle WMSDs, with effect values of 0.221, 0.105, 0.095, and 0.077, respectively. The organization and type of work can also have indirect effects through feet and ankle muscle fatigue, with effect values of 0.121 and 0.084, respectively.Conclusion:Feet and ankle muscle fatigue has a direct impact on WMSDs, and plays a mediating role between ankle and ankle WMSDs caused by work organization and work type. Feet and ankle muscle fatigue is an important pathway leading to feet and ankle WMSDs. It is recommended that employers and managers detect job fatigue early and take corresponding prevention and intervention measures, which can play a key role in preventing feet and ankle WMSDs.
6.Structural equation analysis and modeling of upper limb WMSDs and their adverse ergonomic factors
Siwu ZHONG ; Ning JIA ; Xin SUN ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Gang LI ; Yan YIN ; Hua SHAO ; Jue LI ; Hengdong ZHANG ; Bing QIU ; Dayu WANG ; Qiang ZENG ; Rugang WANG ; Yan YE ; Bin XIAO ; Hua ZOU ; Jianchao CHEN ; Dongxia LI ; Yongquan LIU ; Qinghua SHI ; Jixiang LIU ; Enfei JIANG ; Jun QI ; Liangying MEI ; Xianfeng ZHAO ; Mimi YANG ; Xinwei GUO ; Zhi WANG ; Zhongxu WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(4):254-263
Objective:To explore the structural relationship between WMSDs in the upper limbs and various risk factors in the occupational population in China, based on a large sample epidemiological survey and structural equation analysis, and to establish a structural equation model, so as to lay a foundation for the prevention and control of such diseases.Methods:The Chinese version of the Musculoskeletal Disorders Electronic Questionnaire was used to conduct a nationwide survey on the prevalence of WMSDs in the upper extremity. Six factors related to WMSDs in the upper extremity were extracted by the classification standard of adverse ergonomic factors and their source and confirmatory factor analysis, including work organization, work type, upper extremity work posture, individual factors, upper extremity fatigue and upper extremity WMSDs. The structural equation analysis was carried out and the structural equation model was established.Results:The incidence of WMSDs and fatigue in the upper limbs was 24.44% and 43.76%, respectively. The adjusted structural equation model fitting indicators were generally up to the standard (GFI=1.000, AGFI=1.000, RMSEA=0.043, NFI=0.808, TLI=0.784) . The four exogenous latent variables of work organization, work type, upper limb work posture and individual factors were correlated. There was a strong positive correlation between job type and upper limb work posture ( r=0.865) , a moderate positive correlation between work organization and job type and upper limb work posture ( r=0.570, 0.490) , and a weak negative correlation between individual factors and the other three exogenous latent variables. Upper limb work posture and individual factors had direct effects on upper limb WMSDs, and the effect coefficients were 0.10 and 0.06, respectively. Upper limb fatigue played a mediating role between work organization, work type, upper limb work posture and upper limb WMSDs. The effect coefficient was 0.46, and the composition ratios of indirect effects were 100.0%, 100.0%, and 38.3%, respectively. The direct path effect of upper limb work posture, individual factors and upper limb WMSDs was weaker than the mediating path through upper limb fatigue. Conclusion:When carrying out the prevention and control of upper limbWMSDs, it is necessary to comprehensively consider the pathogenesis path of upper limb muscle fatigue and upper limb WMSDs caused by work organization, work type, and upper limb work posture, so as to provide theoretical reference for improving the prevention and control level of such diseases.
7.Multimodal ultrasound of the testis in differentiating subtypes of spermatogenic dysfunction:a preliminary study
Tingting LEI ; Gaoxiang FAN ; Penglin ZOU ; Chao JIA ; Hongmei LIANG ; Jun LIN ; Rong WU ; Lianfang DU ; Zheng LI ; Qiusheng SHI
Chinese Journal of Ultrasonography 2025;34(8):678-685
Objective:To analyze the imaging features of testicular conventional ultrasonography(US),shear wave elastography(SWE),and contrast-enhanced ultrasonography(CEUS)in subtypes of spermatogenic dysfunction(focal,arrest,and exhausted),and to evaluate the diagnostic efficacy of testicular multimodal ultrasound.Methods:A prospective study enrolled 310 spermatogenic dysfunction patients(focal type group: n=77,arrest type group: n=20,exhaustive type group: n=213)and 30 healthy volunteers(control group)at Shanghai General Hospital between October 2023 and December 2024. All patients underwent preoperative testicular US,SWE,and CEUS examinations,followed by microdissection testicular sperm extraction. Ultrasound parameters were compared among groups,and receiver operating characteristic(ROC)curves were plotted to assess the diagnostic efficacy of multimodal ultrasound for different subtypes. Results:①Testicular volume:The arrest group exhibited significantly greater volume compared to the focal group and the exhausted group(all P<0.05). No statistically significant difference was observed between the arrest group and the normal group( P>0.05). ②Mean Young's modulus(Emean):The arrest group exhibited significantly lower Emean compared with both the focal and exhausted groups(all P<0.05),but showed no significant difference versus the normal group( P>0.05). ③CEUS quantitative parameters:The arrival time(AT)and time to peak(TTP)in the exhausted group were higher than those in the normal group,while the peak intensity(PI)and area under the time-intensity curve(AUC)were lower(all P<0.05). No significant differences were found in AT,TTP,or AUC among the three spermatogenic dysfunction subgroups(all P>0.05). ④CEUS perfusion patterns:The focal group predominantly exhibited a mottled pattern(70.13%,54/77). Both the arrest group(90.00%,18/20)and the normal group(93.33%,28/30)predominantly exhibited an rich pattern. The exhausted group predominantly exhibited a sparse pattern(56.34%,120/213). ⑤ROC curve analysis showed that for differentiating the arrest group from the focal type group and the exhaustive type group,the combination of Emean,testicular volume,and CEUS perfusion pattern yielded an AUC of 0.931,with a sensitivity of 95.00% and specificity of 85.86%. For differentiating the focal type group from the exhaustive type group,the combination of testicular echogenicity,CEUS perfusion pattern,and Emean yielded an AUC of 0.833,with a sensitivity of 81.82% and specificity of 75.12%. Conclusions:Multimodal ultrasonography can comprehensively characterize the imaging features of different subtypes of spermatogenic dysfunction,holding promise as a noninvasive predictive tool.
8.Structural equation analysis of the incidence of shoulder WMSDs and individual and work-related factors
Shuang ZHOU ; Zhongxu WANG ; Ruijie LING ; Qing XU ; Huadong ZHANG ; Yimin LIU ; Gang LI ; Yan YIN ; Hua SHAO ; Jue LI ; Hengdong ZHANG ; Bing QIU ; Dayu WANG ; Qiang ZENG ; Yan YE ; Bin XIAO ; Hua ZOU ; Jianchao CHEN ; Dongxia LI ; Yongquan LIU ; Jixiang LIU ; Enfei JIANG ; Jun QI ; Liangying MEI ; Xianfeng ZHAO ; Mimi YANG ; Ning JIA
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(2):91-100
Objective:To investigate the incidence of shoulder work-related musculoskeletal disorders (WMSDs) among occupational population in China, and to explore their intrinsic association with personal and work-related factors.Methods:In April 2024, 73497 valid questionnaires of the Chinese version of the Musculoskeletal Disorders Electronic Questionnaire were retrospectively analyzed from June 2018 to December 2023 in 22 provinces and 29 key industries in China, and the general information, occurrence of WMSDs and related risk factors of key occupational populations in different regions in China were collected. By using Chi-square test and confirmatory factor analysis, the relationship between shoulder fatigue and pain in key occupational groups and individual factors, work type, work posture and work organization was discussed, and the internal relationship was analyzed based on structural equation model.Results:Higher incidence of shoulder fatigue and pain were associated with female, lack of physical exercise, uncomfortable working posture and neck leaning forward ( P<0.05). Structural equation model analysis showed that work type, work posture and work organization were strongly correlated ( r=0.58, 0.55). Work organization and work type were strongly correlated with shoulder fatigue ( r=0.65) and moderately correlated with shoulder fatigue ( r=0.21). Shoulder fatigue was moderately associated with shoulder pain ( r=0.40). Individual factors, work type, work posture and shoulder fatigue could directly affect shoulder pain ( OR=0.07, -0.09, 0.17 and 0.40), and work type and work posture could also indirectly affect shoulder pain through shoulder fatigue ( OR=0.08, 0.03). Work organization only indirectly affected shoulder pain through shoulder fatigue ( OR=0.26) . Conclusion:The main influencing factor of shoulder pain is shoulder fatigue, followed by work posture and individual factors. Structural equation model can better reflect the complex relationship between work type, work posture and work organization and shoulder WMSDs. Improving work posture and work organization may be an effective way to control the influence of shoulder fatigue on shoulder pain.
9.Structural equation analysis and modeling of fect and ankles WMSDs and its adverse ergonomic factors
Xi ZHANG ; Ning JIA ; Xin SUN ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Gang LI ; Yan YIN ; Hua SHAO ; Hengdong ZHANG ; Yanmin QI ; Bing QIU ; Tiebing LIU ; Dayu WANG ; Qiang ZENG ; Yan YE ; Bin XIAO ; Hua ZOU ; Jianchao CHEN ; Dongxia LI ; Yongquan LIU ; Jixiang LIU ; Enfei JIANG ; Jun QI ; Liangying MEI ; Tianlai LI ; Mimi YANG ; Xinwei GUO ; Zhongxu WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(2):101-109
Objective:To explore the structural equation model to explore the levels of work-related musculoskeletal disorders (WMSDs) and various risk factors in the feet and ankle of China's occupational population, providing scientific basis for for preventing WMSDs in feet and ankles.Methods:Data of 73497 national occupational epidemiological cases were selected from June 2018 to December 2023 used the Chinese version of the Electronic Questionnaire on Musculoskeletal Disorders. The adverse ergonomic factors and their source classification standard and confirmatory factor analysis were used to investigate foot and ankle WMSDs and their related risk factors (including individual factors, work organization, work posture, work type, fatigue, etc.) in key occupational groups in China, and structural equation model hypothesis, fitting, verification, and path and intermediary effect analysis were carried out. The model fit evaluation indexes included Chi-square specific degrees of freedom ( χ2/ df), gauge fit index (NFI), Tucker Lewis index (TLI), goodness of Fit index (GFI), adjusted Goodness of Fit index (AGFI) and approximate root mean square error (RMSEA) . Results:A total of 73497 occupational workers were surveyed, with local muscle fatigue and WMSDs incidence rates in the feet and ankles being 17.17% and 12.06%, respectively. The fitting index of the adjusted structural equation model basically meets the standard (GFI=1, AGFI=1, RMESA=0.042, NFI=0.716, TLI=0.663). The top three factors affecting feet and ankle WMSDs are feet and ankle muscle fatigue, work type, and work organization, with standardized path coefficients of 0.221, 0.105, and 0.095, respectively. The top two factors affecting feet and ankle muscle fatigue are work organization and work type, with standardized path coefficients of 0.548 and 0.383, respectively. Feet and ankle muscle fatigue, work type, work organization, and work posture have a direct effect on feet and ankle WMSDs, with effect values of 0.221, 0.105, 0.095, and 0.077, respectively. The organization and type of work can also have indirect effects through feet and ankle muscle fatigue, with effect values of 0.121 and 0.084, respectively.Conclusion:Feet and ankle muscle fatigue has a direct impact on WMSDs, and plays a mediating role between ankle and ankle WMSDs caused by work organization and work type. Feet and ankle muscle fatigue is an important pathway leading to feet and ankle WMSDs. It is recommended that employers and managers detect job fatigue early and take corresponding prevention and intervention measures, which can play a key role in preventing feet and ankle WMSDs.
10.Structural equation analysis and modeling of upper limb WMSDs and their adverse ergonomic factors
Siwu ZHONG ; Ning JIA ; Xin SUN ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Gang LI ; Yan YIN ; Hua SHAO ; Jue LI ; Hengdong ZHANG ; Bing QIU ; Dayu WANG ; Qiang ZENG ; Rugang WANG ; Yan YE ; Bin XIAO ; Hua ZOU ; Jianchao CHEN ; Dongxia LI ; Yongquan LIU ; Qinghua SHI ; Jixiang LIU ; Enfei JIANG ; Jun QI ; Liangying MEI ; Xianfeng ZHAO ; Mimi YANG ; Xinwei GUO ; Zhi WANG ; Zhongxu WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(4):254-263
Objective:To explore the structural relationship between WMSDs in the upper limbs and various risk factors in the occupational population in China, based on a large sample epidemiological survey and structural equation analysis, and to establish a structural equation model, so as to lay a foundation for the prevention and control of such diseases.Methods:The Chinese version of the Musculoskeletal Disorders Electronic Questionnaire was used to conduct a nationwide survey on the prevalence of WMSDs in the upper extremity. Six factors related to WMSDs in the upper extremity were extracted by the classification standard of adverse ergonomic factors and their source and confirmatory factor analysis, including work organization, work type, upper extremity work posture, individual factors, upper extremity fatigue and upper extremity WMSDs. The structural equation analysis was carried out and the structural equation model was established.Results:The incidence of WMSDs and fatigue in the upper limbs was 24.44% and 43.76%, respectively. The adjusted structural equation model fitting indicators were generally up to the standard (GFI=1.000, AGFI=1.000, RMSEA=0.043, NFI=0.808, TLI=0.784) . The four exogenous latent variables of work organization, work type, upper limb work posture and individual factors were correlated. There was a strong positive correlation between job type and upper limb work posture ( r=0.865) , a moderate positive correlation between work organization and job type and upper limb work posture ( r=0.570, 0.490) , and a weak negative correlation between individual factors and the other three exogenous latent variables. Upper limb work posture and individual factors had direct effects on upper limb WMSDs, and the effect coefficients were 0.10 and 0.06, respectively. Upper limb fatigue played a mediating role between work organization, work type, upper limb work posture and upper limb WMSDs. The effect coefficient was 0.46, and the composition ratios of indirect effects were 100.0%, 100.0%, and 38.3%, respectively. The direct path effect of upper limb work posture, individual factors and upper limb WMSDs was weaker than the mediating path through upper limb fatigue. Conclusion:When carrying out the prevention and control of upper limbWMSDs, it is necessary to comprehensively consider the pathogenesis path of upper limb muscle fatigue and upper limb WMSDs caused by work organization, work type, and upper limb work posture, so as to provide theoretical reference for improving the prevention and control level of such diseases.

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