1.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.
2.Two-sample Mendelian randomization of causal relationship between intestinal flora and ankylosing spondylitis
Renjie LU ; Wenjun SHI ; Shaoyang LIU ; Shuo GE ; Guangyue LIU ; Jixiang SHI
Chinese Journal of Immunology 2025;41(9):2055-2060
Objective:To investigate causal relationship between intestinal flora and risk of developing ankylosing spondylitis(AS)by a two-sample Mendelian randomization(MR)analysis.Methods:Genome-wide association study(GWAS)data on 211 types of intestinal flora and AS were obtained,and single nucleotide polymorphism(SNP)was used as an instrumental variable and sensi-tive SNPs were selected for analysis.Two-sample MR analyses were performed by inverse variance weighted(IVW)as well as MR-Eg-ger,Weighted median,to assess causal relationship between AS and intestinal flora by OR,and results were tested for heterogeneity and pleiotropy.Results:IVW analysis showed a significant causal relationship between 11 intestinal flora and AS risk.Among them,Verrucomicrobiae,Verrucomicrobiales,Verrucomicrobiaceae,Akkermansia,Erysipelatoclostridium,Holdermannia,Holdemania,Bacillales and Verrucomicrobia had positive causal effect on AS risk,while Dialister,Howardella and Oscillospira had negative causal effect.Causal effect estimates obtained by different methods(MR-Egger,Weighted median)were consistent,and sensitivity tests did not reveal significant horizontal pleiotropy and heterogeneity.Conclusion:Intestinal flora plays an important role in pathogenesis of AS,while specific mechanism remains to be further investigated.
3.Two-sample Mendelian randomization of causal relationship between intestinal flora and ankylosing spondylitis
Renjie LU ; Wenjun SHI ; Shaoyang LIU ; Shuo GE ; Guangyue LIU ; Jixiang SHI
Chinese Journal of Immunology 2025;41(9):2055-2060
Objective:To investigate causal relationship between intestinal flora and risk of developing ankylosing spondylitis(AS)by a two-sample Mendelian randomization(MR)analysis.Methods:Genome-wide association study(GWAS)data on 211 types of intestinal flora and AS were obtained,and single nucleotide polymorphism(SNP)was used as an instrumental variable and sensi-tive SNPs were selected for analysis.Two-sample MR analyses were performed by inverse variance weighted(IVW)as well as MR-Eg-ger,Weighted median,to assess causal relationship between AS and intestinal flora by OR,and results were tested for heterogeneity and pleiotropy.Results:IVW analysis showed a significant causal relationship between 11 intestinal flora and AS risk.Among them,Verrucomicrobiae,Verrucomicrobiales,Verrucomicrobiaceae,Akkermansia,Erysipelatoclostridium,Holdermannia,Holdemania,Bacillales and Verrucomicrobia had positive causal effect on AS risk,while Dialister,Howardella and Oscillospira had negative causal effect.Causal effect estimates obtained by different methods(MR-Egger,Weighted median)were consistent,and sensitivity tests did not reveal significant horizontal pleiotropy and heterogeneity.Conclusion:Intestinal flora plays an important role in pathogenesis of AS,while specific mechanism remains to be further investigated.
4.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.
5.Efficacy observation of clinical medication guided by genetic testing of antipsychotic drugs in patients with schizophrenia
Haiyan WANG ; Jianfeng CAO ; Liping FU ; Liangcheng XIANG ; Tao TIAN ; Jixiang WANG ; Ming SHI ; Xiaojun LI ; Chunguang TANG
Sichuan Mental Health 2024;37(5):420-426
Background Results of genetic testing for antipsychotic drugs can guide the rational use of drugs in clinical practice and help improve the clinical symptoms of patients with schizophrenia.However,there is currently limited evidence in China regarding the impact of genetic testing results on medication adherence,social function and drug side effects of antipsychotic drug treatment.Objective To explore the improvement of clinical symptoms,medication adherence and social function in patients with schizophrenia under the guidance of antipsychotic drug gene testing results and examine the safety of drug treatment,so as to provide references for ifor precise treatment of schizophrenia patients.Methods Patients with acute schizophrenia who received hospitalization at Dazhou Minkang Hospital from July 2019 to August 2021 as well as met the diagnostic criteria of the International Classification of Diseases,tenth edition(ICD-10)were selected as research subjects(n=144).Based on random number table,subjects were divided into study group and control group,with 72 cases in each group.Control group received drug treatment based on the doctor's clinical experience,while study group received drug treatment based on the results of gene testing for antipsychotic drug.Both treatments lasted for 12 weeks.At baseline as well as 2,4,8 and 12 weeks after treatment,Positive and Negative Syndrome Scale(PANSS),8-item Morisky Medication Adherence Scale(MMAS-8),Social Functional Rating Scale(SFRS)and Treatment Emergent Symptom Scale(TESS)were adopted for assessment.Result Time effect and group effect of the reducing rate of PANSS,MMAS-8 and SFRS scores in the groups were statistically significant(Ftime=95.251,6.650,14.101,Fgroup=38.055,58.175,128.221,P<0.01).The interaction effect of the reduction rates of MMAS-8 scores in two groups was statistically significant(Finteraction=5.837,P<0.01).The group effect and interaction effect of the severity scores of drug side effects and patient pain scores in two groups were statistically significant(Fgroup=7.553,81.533,Finteraction=8.693,9.322,P<0.01).Conclusion In terms of improving clinical symptom relief,medication adherence,social function and drug side effects,medication for patients with schizophrenia guided by genetic testing of antipsychotic drugs may be more effective than that relying on medication based on clinical experience.
6.Construction of a recombinant Bacillus subtilis strain expressing SpaA and CbpB of Erysipelothrix rhusiopathiae and evaluation of the strain immunogenicity in a mouse model.
Zhonglin CHENG ; Hao HUANG ; Siyi CAO ; Huahui SHI ; Jiye GAO ; Jixiang LI
Chinese Journal of Biotechnology 2024;40(12):4521-4532
To construct a recombinant Bacillus subtilis strain expressing SpaA and CbpB of Erysipelothrix rhusiopathiae for oral administration, we constructed the recombinant plasmid pDG1730-CBJA by fusion PCR and seamless cloning. The plasmid was introduced into B. subtilis KC strain by natural transformation, and the recombinant strain KC-spaA-cbpB was screened out on the plate containing spectinomycin (sper) and confirmed by PCR and starch degradation test. The SpaA and CbpB expressed by KC-spaA-cbpB were detected by Western blotting and indirect immunofluorescence assay, and the genetic stability of the recombinant strain in mice was determined. The plasmid pMAD-∆sper with knockout of sper was constructed and transformed into KC-spaA-cbpB. The sper-deleted mutant strain KC-spaA-cbpB: : ∆sper was screened and identified, and its immunogenicity in a mouse model was evaluated by oral immunization. The results showed that the recombinant strain KC-spaA-cbpB was stable in mice, expressing SpaA on the cell surface and CbpB on the spore surface. KC-spaA-cbpB: : ∆sper expressed SpaA and CbpB. The mice vaccinated with the spores of KC-spaA-cbpB: : ∆sper had higher levels of SpaA and CbpB-specific IgG in the serum that those vaccinated with the wild-type spores 42 days after vaccination by gavage (P < 0.01). The protective rate of mice immunized with the recombinant spores was 67.5%. The results indicated that a recombinant B. subtilis strain expressing SpaA and CbpB of E. rhusiopathiae was successfully constructed, and the recombinant strain laid a foundation for the development of oral live vector vaccines for swine erysipelas.
Animals
;
Bacillus subtilis/immunology*
;
Mice
;
Erysipelothrix/immunology*
;
Bacterial Proteins/immunology*
;
Bacterial Vaccines/genetics*
;
Erysipelothrix Infections/prevention & control*
;
Immunization
;
Mice, Inbred BALB C
;
Plasmids/genetics*
;
Immunogenicity, Vaccine
;
Administration, Oral
;
Antigens, Bacterial
7.Biomechanical study of screw implant angle in reconstruction of tibiofibular syndesmosis injury.
Lei ZHANG ; Minghui LI ; Mengyao ZHANG ; Jixiang XIONG ; Junqiu WANG ; Xin ZHOU ; Houyin SHI ; Guoyou WANG
Chinese Journal of Reparative and Reconstructive Surgery 2024;38(12):1480-1485
OBJECTIVE:
To investigate ideal screw implant angle in reconstruction of tibiofibular syndesmosis injury by using a biomechanical test.
METHODS:
A total of 24 ankle specimens from adult cadavers were used as the tibiofibular syndesmosis injury model. According to the angle of screw placement, the tibiofibular syndesmosis injury models were randomly divided into groups A (0°), B (10°-15°), C (20°-25°), and D (30°-35°), and the screws were placed at a level 2 cm proximal to the ankle joint. The displacement of fibula was measured by biomechanical testing machine at neutral, dorsiflexion (10°), plantar flexion (15°), varus (10°), and valgus (15°) positions, with axial load of 0-700 N (pressure separation test). The displacement of fibula was also measured at neutral position by applying 0-5 N·m torque load during internal and external rotation (torsional separation test).
RESULTS:
In the pressure separation test, group C exhibited the smallest displacement under different positions and load conditions. At neutral position, significant differences were observed ( P<0.05) between group A and group C under load of 300-700 N, as well as between group B and group C under all load conditions. At dorsiflexion position, significant differences were observed ( P<0.05) between group A and group C under load of 500-700 N, as well as between groups B, D and group C under all load conditions, and the displacements under all load conditions were significantly smaller in group A than in group B ( P<0.05). At plantar flexion position, significant differences were observed ( P<0.05) between group D and group C under all load conditions. At valgus position, significant differences were observed ( P<0.05) between group A and group C under load of 400-700 N, as well as between groups B, D and group C under all load conditions. In the torsional separation test, group C exhibited the smallest displacement and group B had the largest displacement under different load conditions. During internal rotation, significant differences were observed ( P<0.05) between group B and group C under all load conditions, as well as between group D and group C at load of 3-5 N·m. During external rotation, significant differences were observed between groups B, D and group C under all load conditions ( P<0.05). No significant difference was detected between groups at the remaining load conditions ( P>0.05).
CONCLUSION
The ideal screw implant angle in reconstruction of tibiofibular syndesmosis injury was 20°-25°, which has a small displacement of fibula.
Humans
;
Bone Screws
;
Biomechanical Phenomena
;
Fibula/injuries*
;
Fracture Fixation, Internal/methods*
;
Adult
;
Ankle Joint/surgery*
;
Ankle Injuries/surgery*
;
Tibia/surgery*
;
Male
;
Range of Motion, Articular
;
Weight-Bearing
;
Female
;
Cadaver
;
Plastic Surgery Procedures/methods*
8.Study on the epidemiological characteristics of work-related musculoskeletal disorders among 29 industries or occupational groups in China
Ning JIA ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Zhi WANG ; 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 ; Xin SUN ; Zhongxu WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2024;42(12):884-895
Objective:To analyze the distribution characteristics of work-related musculoskeletal disorders (WMSDs) among the occupational population in China's key industries during the period from 2018 to 2023, and to provide data support for the formulation of targeted prevention strategies.Methods:Between January 1, 2018, and December 31, 2023, a cross-sectional epidemiological survey and a retrospective investigation were conducted in seven geographical regions of North China, East China, Central China, South China, Southwest China, Northwest China, and Northeast China, using a combination of epidemiological cross-sectional and retrospective surveys. The industries were stratified according to the degree of closeness to WMSDs, the size of the occupational population, and the importance of the national economy, and then cluster sampling was conducted according to the size of the enterprises (large, medium, and small) within each stratum. Representative enterprises were selected, and workers who had been employed for more than one year and met the inclusion criteria were selected as the study subjects. The survey subjects completed the Chinese version of the Musculoskeletal Disorders Survey Questionnaire online by scanning a QR code. A total of 88, 609 valid questionnaires were collected. Continuous data were described by means and standard deviations, and the standardized incidence rates of WMSDs were evaluated using chi-square tests to compare the standardized incidence rates of different body parts.Results:The standardized prevalence rate of WMSDs among the frontline working population in China was 36.7%, with the top three being the neck (21.37%), shoulders (18.23%), and lower back (14.92%). There was a statistically significant difference in the standardized prevalence rate of WMSDs between different body parts (χ 2=47577.82, P<0.05). The lowest standardized prevalence rate of WMSDs was found in the southeast coastal region of China (32.54%), while the highest was in the northwest (49.70%) and northeast regions (46.16%). The standardized prevalence rate of WMSDs decreased from 42.88% in 2018 to 29.94% in 2023. The micro-enterprise observation group had a higher concentration of WMSDs in the neck (20.66%), lower back (17.95%), and shoulders (17.79%), while the large enterprise observation group had a higher concentration in the neck (20.54%), shoulders (17.52%), and lower back (14.65%). Among the industries surveyed, the highest standardized prevalence rate of WMSDs was found in the healthcare industry (53.18%), followed by the toy manufacturing industry (50.54%), the automotive manufacturing industry (43.39%), general aviation services (42.71%), and the ship and related equipment manufacturing industry (40.56%). The standardized prevalence rate of WMSDs among women was significantly higher than that of men ( OR value=1.44, P<0.05). In addition, the standardized prevalence rate of WMSDs with multiple affected body parts (four or more body parts affected simultaneously) was higher, and the risk of WMSDs increased with subjective fatigue, showing a significant "S-shaped" trend (the OR value was 2.19, 3.16, 4.71, 5.49, and 3.97 when the RPE was 13, 15, 17, 19, and 20, respectively. χ 2trend=17.23, P<0.001) . Conclusion:The distribution characteristics of WMSDs in key industries in China show obvious differences in different parts, regions, time, enterprise scale, industry and population attributes. Agriculture, pharmaceutical manufacturing, packaging and decoration and other printing industries have a high proportion of WMSDs in multiple parts at the same time and in a single site. It is necessary to study and implement precise preventive measures according to specific regions, industries and enterprise scales, as well as the characteristics of multi-site WMSDs, so as to effectively protect the health and well-being of the working population.
9.Study on the relationship between occupational exposure characteristics and musculoskeletal disorders in 29 industries or workforce groups in China
Ning JIA ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Zhi WANG ; 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 ; Xianfng ZHAO ; Mimi YANG ; Xinwei GUO ; Xin SUN ; Zhongxu WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2024;42(12):896-910
Objective:To explore the occupational contact characteristics of work-related musculoskeletal disorders (WMSDs) among key occupational groups in China, assess the impact of occupational factors on the occurrence of WMSDs, and propose corresponding preventive strategies.Methods:Between January 1, 2018, and December 31, 2023, a cross-sectional epidemiological survey method was employed to retrospectively investigate the occurrence of WMSDs and related occupational factors. Valid questionnaire data from 88609 on-the-job workers in 441 enterprises across 29 industries or job types in seven regions of China were collected, and the relationship between WMSDs and various occupational factors was discussed using multifactorial logistic regression analysis. Odds ratios ( OR) and their 95% confidence intervals ( CI) were calculated to assess the impact of different factors on the risk of WMSDs occurrence, with all statistical tests performed as two-tailed tests, using P<0.05 as the criterion for statistical significance. Results:Among the surveyed subjects, 59989 were male, accounting for 67.7% (59989/88609) ; 28620 women, accounting for 32.3% (28620/88609). The standardized incidence rate of work related musculoskeletal disorders (WMSDs) in 9 parts of the body was statistically significant ( P<0.05) among different working age groups without considering specific parts. The average length of service for onset of WMSDs (regardless of location) is (4.52±2.67) years, and there is a statistically significant difference in the length of service for onset of WMSDs in different locations ( P<0.05). As the frequency of heavy object handling increases, the standardization rate and OR value of WMSDs in various parts show a significant increase trend. The incidence of WMSDs is significantly correlated with maintaining poor work posture for a long time, frequent repetitive operations, and heavy object handling ( OR=1.52, 1.45, 1.63, P<0.01) . Conclusion:This study reveals that the risk of WMSDs in China's occupational population shows a non-linear change with increasing length of service, especially with a significant increase in 10 to 25 years of service. Poor work posture, frequent repetitive operations, and heavy object handling are significantly correlated with WMSDs, providing a scientific basis for developing more accurate and effective prevention strategies for WMSDs.
10.Structural equation analysis and modeling of wrist WMSDs and its adverse ergonomic factors
Xinwei GUO ; Zhongxu WANG ; Xin SUN ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Zhi WANG ; 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 ; Ning JIA
Chinese Journal of Industrial Hygiene and Occupational Diseases 2024;42(12):927-936
Objective:To investigate the relationships and impacts between various occupational ergonomic hazards and hand and wrist fatigue, as well as work-related musculoskeletal disorders (WMSDs) of the hand and wrist, and to propose targeted preventive and intervention measures for adverse occupational ergonomic factors causing WMSDs of the hand and wrist.Methods:From 2018 to December 2023, a nationwide epidemiologic survey study of wrist WMSDs was conducted using the Chinese version of the electronic questionnaire system for musculoskeletal disorders.A total of 88, 609 valid questionnaires were collected. The exclusion criteria were as follows: patients with congenital spinal deformities, as well as those with wrist WMSDs caused by external injuries, infectious diseases, and malignant tumors. A total of 73, 497 questionnaires were finally included in the study analysis, with an effective questionnaire return rate of 82.5%. Exploratory factor analysis was used to analyze and summarize the factors affecting wrist WMSDs from the questionnaires, including individual factors, work organization, work type, wrist work posture, wrist fatigue, and wrist WMSDs as latent variables, and to hypothesize, fit, and validate the structural aspect model, as well as to conduct mediation effect analysis.Results:The incidence of WMSDs and fatigue in wrist was 12.19% and 16.30% respectively. The fitting indexes of the modified structural equation model were basically up to the standard (GFI was 0.981, AGFI was 0.973, RMSEA was 0.031, NFI was 0.863, IFI and CFI were 0.865). There is a correlation between individual factors, work organization, wrist working posture and work type. There was a low negative correlation between individual factors and other factors, and there was a positive correlation between work organization, work type and wrist WMSDs ( r=0.346, 0.295), and these two factors were positively correlated with wrist fatigue height ( r=0.862, 0.599), and were positively correlated with wrist working posture ( r=0.443, 0.620). There was moderate positive correlation between wrist working posture and wrist fatigue ( r=0.469). The three most influential factors on wrist WMSDs were work organization, individual factor and work type, and the path coefficients were 0.247, 0.210 and 0.136, respectively. The first two factors that have the greatest influence on wrist fatigue are work organization and work type, and the path coefficients are 0.758 and 0.188, respectively. Individual factors, work type, wrist working posture and work organization had direct effects on wrist WMSDs, and the effect values were 0.093, 0.253, 0.718 and 0.583, respectively. Wrist fatigue played a partial mediating role between individual factors, work type, wrist working posture and work organization and wrist WMSDs, with the indirect effect ratio of 25.6%, 45.8%, 3.2% and 65.5%. Conclusion:Wrist fatigue plays an important mediating role in the path of various factors affecting wrist WMSDs, especially in the path of work organization, work type, individual factors and wrist WMSDs. Poor wrist working posture is an important risk factor that directly affects the occurrence of wrist WMSDs.

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