Bus drivers, as an important occupational group in urban public transportation system, are prone to suffer from work-related musculoskeletal disorders (WMSDs) due to prolonged fixed postures and repetitive movements. The T/WSJD 14.9-2024 Ergonomic Guidelines for the Prevention of Work-related Musculoskeletal Disorders: Part 9: Bus Driving Work is a recommended standard developed to prevent WMSDs among bus drivers. This standard, guided by the principles of T/WSJD 14.1-2020 Ergonomic Principle for the Prevention of Work-related Musculoskeletal Disorders: Part 1: General Principles, is based on a preliminary work of comprehensive review of domestic and international research, workplace on-site surveys and questionnaires, data analysis, and factor identification. It defines the scope of application, identifies relevant risk factors and potential affected body parts, and offers ergonomic solutions in the form of intervention examples. The issuance of this guideline as a organization standard will facilitate the promotion and implementation of intervention measures.

Objective To investigate the changes of brain networks function in patients with primary dysmenorrhea(PDM)during menstruation based on topological attributes of brain network.Methods Brain resting-state functional MRI of 57 PDM patients(PDM group)and 50 healthy women(health control[HC]group)were prospectively collected within the first or the second day of menstruation.Clinical scores were obtained and compared between groups.Results Visual analogue scale,cox menstrual symptom scale,self-rating anxiety scale and self-rating depression scale scores in PDM group were all higher than those in HC group(all P＜0.05).At the sparsity of 0.04-0.50,brain networks in both groups conformed to the small world attribute characteristics,and no significant difference of global attributes of brain network was found between groups(all P＞0.05).The node efficiency(Ne)and node degree(Dc)of bilateral posterior cingulate gyrus(PCG),as well as De and node betweenness(Bc)of left middle frontal gyrus(MFG)in PDM group were all higher than those in HC group,while Ne and De of left inferior temporal gyrus in PDM group were lower than those in HC group(all P＜0.01).Compared with HC group,the functional connections between left PCG and right calcarine fissure and surrounding cortex,right lingual gyrus and left MFG,as well as between right PCG and right dorsolateral superior frontal gyrus and left MFG,between right insula and left middle occipital gyrus enhanced in PDM group(all P＜0.001).Conclusion In PDM patients,local brain networks function such as default mode network,central executive network and salience network were over-activated during menstruation,yet the overall brain network still had good coordination and organization.

Background Shoemaking industry workers are prone to work-related musculoskeletal disorders (WMSDs) due to long-term awkward postures during the work process. There is little research on the prevalence and influencing factors of WMSDs in the knee region of this industry, and it should be taken seriously. Objective To estimate the prevalence of work-related knee pain among shoemaking workers and analyze the related influencing factors. Methods A total of 6982 shoemaking workers were selected from 26 shoemaking factories in Guangdong, Hubei, Fujian, Chongqing, Shandong, Zhejiang, and Jingxi by convenience sampling. Prevalence of work-related knee pain in past year, demographic characteristics, occupational related factors, and work posture were collected by a cross-sectional survey using the electronic version of Musculoskeletal Disorder Questionnaire. Logistic regression analysis was used to analyze the influencing factors that may lead to work-related knee pain. Results This survey collected 6982 valid questionnaires with a recovery rate of 98.3%. The prevalence of work-related knee pain of shoemaking workers in the past 12 months was 13.0% (908/6982). According to the results of logistic regression analysis, compared with workers with less than 5 years of service, workers with 5-10 years of service (OR=1.21, 95%CI: 1.02, 1.45) and more than 10 years (1.53, 95%CI: 1.27, 1.83) showed a higher risk of knee WMSDs; sometimes, often and very frequent (reference : rarely or never) long-term standing (OR=1.33, 95%CI: 1.08, 1.64; OR=2.67, 95%CI: 2.10, 3.39; OR=2.75, 95%CI: 2.08, 3.63) and sometimes, often and very frequent (reference: rarely or never) long-term squatting or kneeling (OR=1.80, 95%CI: 1.47, 2.21; OR=2.43, 95%CI: 1.58, 3.75; OR=3.22, 95%CI: 1.66, 6.24) increased the risk of knee pain: long-term bending (OR=1.59, 95%CI: 1.34, 1.89) and often repeated movement of lower limbs and ankles (OR=1.48, 95%CI: 1.25, 1.75) were also risk factors for knee WMSDs among shoemaking industry workers (P<0.05). Adequate rest time (OR=0.58, 95%CI: 0.49, 0.68) and able to stretch or change leg posture (OR=0.75, 95%CI: 0.64, 0.88) reduced the risk of knee WMSDs (P<0.05). Conclusion In the shoemaking industry, length of service and awkward postures are risk factors for knee pain. The shoemaking enterprises should ensure that workers have sufficient rest time, reduce long-term standing, squatting, kneeling, and bending postures, as well as lower limbs repetition in order to reduce the occurrence of knee WMSDs of workers.

Background Long-term exposure to whole-body vibration (WBV) will affect the health of occupational drivers. However, research on the characteristics of WBV exposure by urban bus drivers and health risk evaluation is still insufficient. Objective To identify the characteristics of occupational WBV exposure of bus drivers serving 31 bus routes provided by three branches of Haikou Public Transport Group, and to evaluate their occupational health risks related to WBV. Methods A total of 31 out of 142 bus routes run by three branches of Haikou Public Transport Group were selected to monitor WBV exposure of 31 bus drivers during driving. WBV parameters such as triaxial frequency weighted acceleration (a_wx, a_wy, a_wz) and triaxial crest factor (CF_x, CF_y, CF_z) of the drivers were determined with a six-channel human vibration meter. Two methods, 8-hour daily value of the weighted root mean square average weighted vibration [A(8)] based on a_w and 8-hour daily value of vibration dose [VDV(8)] based on vibration dose value (VDV), were used for health risk assessment and classified WBV health risk results into three levels (high, medium, and low) by the exposure action value (EAV) and exposure limit values (ELV) for A(8) and VDV(8) recommended by ISO 2631-1:1997. The two evaluation methods, A(8) and VDV(8), were compared by Fisher's exact test. Results Regarding the WBV parameters, the vector sum of acceleration (a_v) was 0.321-0.680 m·s⁻², the VDV of monitoring interval was 3.824-10.174 m·s^−1.75, and the VDV(8) was 6.039-13.505 m·s^−1.75; their values in mean ± standard deviation were (0.480±0.100) m·s⁻², (6.987±2.737) m·s^−1.75, and (9.773±4.540) m·s^−1.75, respectively. Positive correlations were found between a_wx and a_wz, a_v and a_wz, CF_x and CF_y, CF_y and CF_z. No bus route's WBV exposure level was graded as high health risk by either A(8) or VDV(8). The number of routes graded as low health risk by A(8) was 26, while the number by VDV(8) was 12. The consistency rates of health risk levels evaluated by the two methods were 66.7% (6/9), 54.6% (6/11), and 45.5% (5/11) for the three bus group branches, respectively. The difference in WBV health risk assessment results between the two evaluation methods was not statistically significant. Conclusion Positive correlations are found between triaxial acceleration and triaxial crest factor. There is no difference in the results of using A(8) and VDV(8) to evaluate health risks of WBV in urban bus routes.

Objective:To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in logistics workers of automobile manufacturing enterprises in Guangzhou, and explore their potential categories and influencing factors, so as to provide basis for the prevention and control of WMSDs in logistics workers of automobile manufacturing enterprises.Methods:From April to May 2020, a convenient sampling method was adopted to select 1442 logistics workers in 2 automobile manufacturing enterprises in Guangzhou as the research objects. The incidence of WMSDs among them was investigated by using the Nordic Musculoskeletal Disorders Questionnaire, and the incidence pattern of WMSDs among the subjects was analyzed by the method of potential category analysis. Chi-square test and multiple logistic regression model were used to analyze the influencing factors of the disease.Results:The total prevalence of WMSDs was 42.9% (619/1442). The three parts with high prevalence of WMSDs were neck (23.5%, 339/1442), shoulder (21.3%, 307/1442) and lower back (19.1%, 275/1442). 69.0% (427/619) of the patients showed simultaneous disease in two or more sites. The subjects were divided into four latent groups by the analysis of latent categories: the group with multiple body parts (4.51%), the group with very low or no disease (70.39%), the group with shoulder and neck and upper back (11.37%), and the group with limbs and lower back (13.73%). Multivariate logistic regression showed that compared with the "very low or no disease group", the risk factors of multiple body parts of automotive logistics workers suffering from WMSDs mainly included: Working posture uncomfortable ( OR=3.10, 95% CI: 1.44~6.70, P=0.004), often bend and turn ( OR=2.36, 95% CI: 1.05~5.29, P=0.037), bend your knees homework for a long time ( OR=2.29, 95% CI: 1.17~4.47, P=0.015) ; Working posture uncomfortable ( OR=2.26, 95% CI: 1.51~3.38, P<0.001), bending the neck ( OR=1.68, 95% CI: 1.03~2.74, P=0.036), neck minister time keep the same position ( OR=1.81, 95% CI: 1.22~2.67, P= 0.003) It is a risk factor for shoulder, neck and upper back WMSDs; Risk factors for limb-lower back WMSDs include: Length > 10 years ( OR=2.16, 95% CI: 1.24~3.78, P<0.001), the working position uncomfortable ( OR=2.38, 95% CI: 1.63~3.48, P<0.001), bending the neck ( OR=1.66, 95% CI: 1.03~2.68, P=0.039) . Conclusion:The prevalence rate of WMSDs among logistics workers in automobile manufacturing enterprises is high, which has obvious characteristics of classification and comorbis, and is closely related to individual characteristics such as sufficient rest time and working posture of workers.

Objective:To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in logistics workers of automobile manufacturing enterprises in Guangzhou, and explore their potential categories and influencing factors, so as to provide basis for the prevention and control of WMSDs in logistics workers of automobile manufacturing enterprises.Methods:From April to May 2020, a convenient sampling method was adopted to select 1442 logistics workers in 2 automobile manufacturing enterprises in Guangzhou as the research objects. The incidence of WMSDs among them was investigated by using the Nordic Musculoskeletal Disorders Questionnaire, and the incidence pattern of WMSDs among the subjects was analyzed by the method of potential category analysis. Chi-square test and multiple logistic regression model were used to analyze the influencing factors of the disease.Results:The total prevalence of WMSDs was 42.9% (619/1442). The three parts with high prevalence of WMSDs were neck (23.5%, 339/1442), shoulder (21.3%, 307/1442) and lower back (19.1%, 275/1442). 69.0% (427/619) of the patients showed simultaneous disease in two or more sites. The subjects were divided into four latent groups by the analysis of latent categories: the group with multiple body parts (4.51%), the group with very low or no disease (70.39%), the group with shoulder and neck and upper back (11.37%), and the group with limbs and lower back (13.73%). Multivariate logistic regression showed that compared with the "very low or no disease group", the risk factors of multiple body parts of automotive logistics workers suffering from WMSDs mainly included: Working posture uncomfortable ( OR=3.10, 95% CI: 1.44~6.70, P=0.004), often bend and turn ( OR=2.36, 95% CI: 1.05~5.29, P=0.037), bend your knees homework for a long time ( OR=2.29, 95% CI: 1.17~4.47, P=0.015) ; Working posture uncomfortable ( OR=2.26, 95% CI: 1.51~3.38, P<0.001), bending the neck ( OR=1.68, 95% CI: 1.03~2.74, P=0.036), neck minister time keep the same position ( OR=1.81, 95% CI: 1.22~2.67, P= 0.003) It is a risk factor for shoulder, neck and upper back WMSDs; Risk factors for limb-lower back WMSDs include: Length > 10 years ( OR=2.16, 95% CI: 1.24~3.78, P<0.001), the working position uncomfortable ( OR=2.38, 95% CI: 1.63~3.48, P<0.001), bending the neck ( OR=1.66, 95% CI: 1.03~2.68, P=0.039) . Conclusion:The prevalence rate of WMSDs among logistics workers in automobile manufacturing enterprises is high, which has obvious characteristics of classification and comorbis, and is closely related to individual characteristics such as sufficient rest time and working posture of workers.

Objective: To analyze the current status of work-related musculoskeletal disorders (WMSDs), work fatigue and musculoskeletal pain in Chinese occupational population, and to study the relationship between work fatigue and musculoskeletal pain and WMSDs. Methods: A total of 66 961 employees from 323 enterprises in 15 key industries in China were selected as the study subjects using stratified cluster sampling method. The incidence of WMSDs in the past year was investigated using the Chinese version of the Musculoskeletal Disorders Questionnaire, and the work fatigue and musculoskeletal pain were investigated using Borg 6-20 Rating of Perceived Exertion Scale and visual analogue scale. The data were standardized using the age composition data of 18 to 60 years from the seventh national population census. Results: The standardized annual incidence of WMSDs was higher in the front-line workers than that in the administrative and other supportive staff (38.82% vs 36.30%). The detection rates of work fatigue and musculoskeletal pain in the study subjects were 44.54% and 63.08%, respectively. The result of S-curve fitting showed that the risk of WMSDs increased with the level of work fatigue (P<0.01). Among the front-line workers, the average of monthly fatigue frequency in the neck, shoulder, lower back, upper back, wrist/hand, foot and ankle, knee, leg, and elbow were higher in the group with WMSDs compared to those without WMSDs (all P<0.01). The pain degree of musculoskeletal pain was higher in all nine sites in the fatigued group than in the no-fatigue group (all P<0.01). The standardized detection rate of musculoskeletal pain was higher in the fatigued group than in the non-fatigued group (80.38% vs 25.71%). The work fatigue was moderate and positively correlated with musculoskeletal pain in all seven sites except the lower back and elbow, with Kendall Tau-b correlation coefficients ranging from 0.423 to 0.546 (all P<0.01). Conclusion: There is a good correlation between work fatigue and local musculoskeletal pain, work fatigue and WMSDs in Chinese occupational population. Implementing ergonomic interventions to control the development of work fatigue can be an effective measure for preventing WMSDs.

Objective: The spatial distribution model of particulate matter based on time change in a specific place was established to analyze the spatial and temporal distribution characteristics and movement of particulate matter. Methods: A convenience store was selected as the research subject. The micro-climate and particle number concentration (PNC) of the site were detected, and numerical simulation was carried out by computational fluid dynamics (CFD) simulation method. Based on the discrete phase model, the temporal and spatial distribution characteristics and movement rules of simulated particles were analyzed. Results: The wind speed at the entrance of the convenience store was low and almost unchanged during the detection, while the wind speeds outside and inside outlets were high and changed sharply. The PNC of particle size of 0.02-1.00 μm was higher than that of particle size >1.00 μm (all P<0.05). The PNC with particle size of 0.02-1.00 μm from high to low were checkout counter, entrance, outer outlet and inner outlet (all P<0.05). The PNC of the checkout counter and entrance varies greatly, while the PNC of the outer outlet and inner outlet was relatively steady. The CFD simulation results showed that particles exhaled by individuals near the entrance of the checkout counter of the convenience store could be expelled outdoors more quickly with the influence of airflow. However, particles exhaled by individuals in the middle of the shelves remained suspended indoors for a longer period of time compared to those near the checkout counter. Particles emitted from the air conditioning outlet diffuse throughout the entire store and reach a steady state in 300 seconds. Conclusion: The particulate matter in the convenience store was mainly small particle with the size less than 1.00 μm. The residence time, downward trend and number of suspended particulates of human exhaled particles were related to air flow. The particulates escaped from the air conditioner could quickly spread to almost the entire convenience store.

Background Furniture manufacturing is one of the typical labor-intensive industries, and workers in this industry face a high risk of work-related musculoskeletal disorders (WMSDs), which seriously affect the physical and mental health of workers. Objective To explore the prevalence and potential risk factors of WMSDs among workers in a large-scale furniture manufacturing factory. Methods A cross-sectional study of 3431 workers in a furniture factory in Guangdong Province was conducted from September to December 2019. Information including reported WMSDs in various body parts in the past year, demographic characteristics, work organization factors, job characteristics, and work postures was collected by an electronic version of Musculoskeletal Disorders Questionnaire. Pearson χ² test and binary logistic regression were used to analyze the risk factors leading to WMSDs. Results The overall prevalence rate of WMSDs was 32.12% (1102/3431). The most common WMSDs symptoms occurred in the neck (16.85%), followed by the feet (15.27%), shoulders (14.81%), and hands (14.25%). The prevalence rates of WMSDs in the neck, shoulders, elbows, hands, legs, and feet were significantly different among different types of work (P<0.05). The results of multiple logistic regression analysis showed that individual factors, work organization factors, job characteristics, and awkward work postures were associated with the frequency of reporting WMSDs in specific parts of workers. Comparatively poor physical health (including moderate, poor, and very poor) was positively correlated with neck, shoulder, hand, and foot WMSDs (OR=1.479-4.077); working with an uncomfortable posture (OR=1.983) and doing the same task almost every day (OR=1.783) were positively correlated with neck pain; doing the same task almost every day (OR=2.408) and neck twisting for a long time (OR=1.830) were positively correlated with shoulder pain; bending wrists up and down frequently (OR=1.948) and bending wrists for a long time (OR=2.081) were positively correlated with hand pain; prolonged standing (OR=1.953) and often working overtime (OR=1.627) were positively correlated with feet pain; sufficient rest time was negatively correlated with WMSDs in the neck, shoulders, hands, and foot (OR=0.544-0.717). Conclusion The prevalence rate of WMSDs in furniture manufacturing workers is relatively high, and neck, feet, shoulders, and hands are the most involved body parts. The frequency of reporting WMSDs is related to individual factors, work organization factors, job characteristics, and awkward work postures.

Background Work-related musculoskeletal disorders (WMSDs) are one of the major occupational health problems in the world. Pharmaceutical industry is an important part of China's national economy. At present, there are few related studies reported at home and abroad. Objective To investigate the status and influencing factors of WMSDs in chemical pharmaceutical industry. Methods A cross-sectional epidemiological survey was conducted among all workers from three chemical pharmaceutical enterprises in Guangzhou. The Musculoskeletal Disorders Questionnaire was used to collect information on demographic characteristics, symptoms of musculoskeletal disorders, types of work, work organization, and and work postures. Multiple logistic regression method was used to analyze the risk factors of WMSDs in chemical pharmaceutical workers. Results In this study, 563 workers were selected as subjects. The total prevalence rate of WMSDs symptoms in the chemical pharmaceutical workers was 43.9% (247/563), and the leading body part-specific prevalence rate from high to low was 34.3% in the lower back, 24.3% in the upper back, 24.0% in the shoulders, and 23.8% in the neck. The prevalence rate of WMSDs symptoms in multiple body parts (30.0%) was 2.16 times higher than that in single body part (13.9%), and the prevalence rate of WMSDs symptoms in four body parts was the highest (11.4%). The results of multiple logistic regression analysis showed that age ≥50 years (reference age <30 years) (OR=2.140, 95%CI: 1.054-4.345), often or very often (reference never/rarely) long-time head rotating (OR=2.695, 95%CI: 1.753-4.142) and long-time keeping arms above shoulders (OR=1.902, 95%CI: 1.108-3.265) increased the risk of reporting WMSDs symptoms (P<0.05). Regarding education level, workers with high school and technical secondary school (OR=0.333, 95%CI: 0.175-0.636) or college and above (OR=0.413, 95%CI: 0.216-0.790) education had a lower risk of reporting WMSDs symptoms than those with middle school or below (P<0.05). Conclusion The prevalence rate of reporting WMSDs symptoms in chemical pharmaceutical industry is high, the involving body parts are lower back, upper back, shoulders, and neck, and reporting simultaneous occurrence of WMSDs symptoms in multiple body parts is common. The chemical pharmaceutical manufacturers can reduce the risk of WMSDs by strengthening the training on workers' ergonomics knowledge, paying attention to the less educated personnel, protecting the elderly workers, and avoiding awkward work postures, like rotating head for a long time and raising arms over shoulders.