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.

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.

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.

{L-End}Objective To analyze the prevalence of multi-site work-related musculoskeletal disorders (WMSDs) and their influencing factors among workers in the chemical pharmaceutical industry. {L-End}Methods A total of 563 workers from three chemical pharmaceutical factories in Guangzhou City were selected as the research subjects using the judgment sampling method. The prevalence of multi-site WMSDs in the past 12 months was investigated using the electronic questionnaire of Chinese Version of Musculoskeletal Disorders Questionnaire. {L-End}Results The prevalence of multi-site WMSDs in the research subjects was 30.0% (169/563). The results of multivariable logistic regression analysis showed that workers who smoked regularly/frequently and those who had their hands above shoulder level for long periods of time had a lower risk of multi-site WMSDs than those who never/occasionally smoked (all P≤0.05). Workers with a high school, secondary specialty, college degree, or above had a lower risk of multi-site WMSDs than those with a middle school education or below (all P<0.05). The longer the daily working hours, the higher the risk of multiple WMSDs (all P<0.05). Workers with regular/frequently work shifts had a lower risk of multi-site WMSDs than those with none/occasional work shifts (P<0.05). {L-End}Conclusion The prevalence of multi-site WMSDs among workers in the chemical pharmaceutical industry is relatively high. The influencing factors are individual factors, unreasonable work organization and poor ergonomics factors.

{L-End}Objective To analyze the local muscle response under continuous ergonomic workload by simulating manual lifting, and to screen the sensitive metabolic biomarkers during fatigue process. {L-End}Methods A total of 13 healthy male volunteers were selected as the study subjects using simple random sampling method. Study subjects underwent repetitive simulated manual lifting for four periods (T1 to T4), each lasting 12 minutes. The degree of work-related fatigue in the forearm, upper arm, shoulder, back, and leg muscles, and the whole body was accessed using Borg 6-20 Rating of Perceived Exertion (RPE) Scale. The venous blood samples were collected from elbow between each two periods to detect the levels of eight metabolic biomarkers: ammonia, lactate, creatine kinase, lactate dehydrogenase (LDH), C-terminal telopeptide of type Ⅰ collagen (CTX-Ⅰ), C-terminal telopeptide of type Ⅱ collagen (CTX-Ⅱ), cartilage oligomeric matrix protein (COMP), and calcium ions. {L-End}Results The RPE scores of the study subjects for the muscles of five body parts and the whole body increased with the increasing lifting periods (all P<0.01). Fatigue was observed in all target muscles, with overall body fatigue occurring in the T2 period. The levels of ammonia, lactate, creatine kinase, LDH, COMP, and calcium ions in the serum of study subjects were higher in the T1 to T4 periods than in the T0 period (all P<0.05). The serum CTX-Ⅰ level was higher in the T1 and T3 periods than that in the T0 period (all P<0.05) , and the serum CTX-Ⅱ level was higher in the T1, T2 and T4 periods than that in the T0 period (all P<0.05). The level of these eight serum metabolic biomarkers fluctuated during the T1 to T4 periods. The serum creatine kinase level increased with the period of lifting (all P<0.05). The serum lactate level was higher in the T3 period than those in the T1 and T2 periods (all P<0.05). The serum LDH and calcium ion levels were higher in the T2 to T4 periods than that in the T1 period (all P<0.05). The serum COMP level was higher in the T2 and T3 periods than that in the T1 period (all P<0.05). Except for CTX-Ⅰ, the levels of other seven metabolic markers in serum were higher in individuals after fatigue than before fatigue (all P<0.05). {L-End}Conclusion Serum metabolic biomarkers such as ammonia, lactate, creatine kinase, calcium ions, LDH, CTX-Ⅱ, and COMP exhibit significant changes before and after fatigue. These metabolic biomarkers could be used as sensitive biomarkers for evaluating muscle fatigue during repetitive works.

{L-End}Objective To investigate the current status and influencing factors of leg work-related musculoskeletal disorders (WMSDs) in shipbuilding workers. {L-End}Methods A total of 3 393 shipbuilding workers from Guangdong Province, Liaoning Province, Shandong Province, and Beijing City were selected as the research subjects using the convenience sampling method. The Chinese Version of the Musculoskeletal Disorders Questionnaire was used to investigate the prevalence of leg WMSDs in the past year. A multivariate logistic regression model was used to analyze the influencing factors of leg WMSDs. {L-End}Results The prevalence of leg WMSDs in the research subjects was 11.3% (382/3 393). The result of multivariate logistic regression showed that the risk of leg WMSDs was higher in workers with a length of service >10 years than those with a length of service <5 years (P<0.05). Workers with frequent used of vibration tools at work had higher the risk of leg WMSDs (all P<0.05). Workers who did the same work every day, had insufficient rest time, had a shortage of department staff, and those who often repeated the same leg movements had a higher risk of leg WMSDs (all P<0.05). The risk of leg WMSDs in workers who sometimes stand for a long time was lower than that in workers who rarely stand for a long time (P<0.01). {L-End}Conclusion Length of service, rarely long-standing work, use of vibration tools at work, daily engagement in the same work, in-adequate rest time, shortage of department staff, and frequent repetition of the same leg movements are all influencing factors for leg WMSDs in shipbuilding workers.

AIM: To explore the effect of spinal anesthesia on ventricular arrhythmia and involved mechanisms in myocardial ischemia-reperfusion (MIR) rats. METHODS: The rat MIR model was made by occlusion the left anterior descending coronary artery for 30 minutes and reperfusion for 45 minutes. Bupivacaine (0.05 mL / 100 g, 1 mg / kg) was injected slowly via intrathecal for spinal anesthesia. The electromyelogram at T2 thoracic spinal cord was recorded. Ventricular arrhythmias, cardiac function, myocardial damage were assessed by electrocardiography, echocardiography and TTC or HE staining. RESULTS: MIR reduced left ventricular short-axis shortening (LVFS) and left ventricular ejection fraction (LVEF), caused myocardial histological damage and ventricular arrhythmias, promoted spinal electrical discharge frequency and amplitude in T2 dorsal horn. Spinal injection of bupivacaine could significantly reduce spinal cord electrical activities and eliminate MIR-induced arrhythmias. Moreover, bupivacaine also significantly improved MIR-induced myocardial histological damage and cardiac function inhibition. CONCLUSION: Spinal anesthesia can reduce ventricular arrhythmias induced by MIR. The mechanism may be related to the effect of abolishing spinal nerve excitability.

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.