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 Prolonged awkward postures during occupational activities can lead to excessive musculoskeletal load on the wrist of workers and symptoms such as wrist pain or discomfort. Objective To survey the prevalence of wrist pain among workers in 10 key industries and analyze its correlation with wrist working postures. Methods By using stratified cluster sampling method, workers from 10 key industries, such as footwear manufacturing industry, shipbuilding manufacturing industry, and automobile manufacturing industry, were selected from seven regions in North China, East China, Central China, South China, Southwest China, Northwest China, and Northeast China. The demographic information, wrist working postures, pain in wrist of the workers were collected through a cross-sectional survey. Pearson χ² test was used to compare prevalence by selected factors, trend χ² test for between group comparison, and unconditional logistic regression models for the association of wrist working postures with wrist pain. Results There were 64052 workers enrolled in this survey, and 56286 provided valid questionnaires (the effective rate was 87.8%). According to the survey, the prevalence of wrist pain was 23.3% (13112/56286), and the industries with higher prevalences were footwear manufacturing (27.1%, 1927/7106), automobile manufacturing (24.9%, 5378/21560), and shipbuilding and related equipment manufacturing (24.4%, 850/3488) industries. Finger pinching (OR=2.09, 95%CI: 1.95-2.24), frequent wrist bending (OR=2.03, 95%CI: 1.92-2.15), fixed wrist bending (OR=1.77, 95%CI: 1.69-1.85), wrist on hard edge (OR=1.34, 95%CI: 1.28-1.40), and arms over shoulders (OR=1.11, 95%CI: 1.05-1.17) increased the risk of reporting wrist pain. Conclusion Awkward postures are related to wrist pain among workers in selected 10 key industries. The related factors are wrist on hard edge, frequent wrist bending, finger pinching, fixed wrist bending, and arms over shoulders.

{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 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.

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.

Objective:To investigate the feasibility of single breath-hold TFE-EPI in non-contrast coronary MRA on 3.0 T MRI.Methods:Both single breath-hold TFE-EPI and free breathing TFE were conducted in 23 healthy volunteers. Acquisition time between the two sequences were compared by paired- t-test analysis. Signal-noise-ratio (SNR), contrast-noise-ratio (CNR),image artifacts and distortion,vessel acuity were evaluated on the aorta(Ao), right coronary artery proximal(RCA-pro), right coronary artery middle (RCA-mid), left anterior descending proximal(LAD-pro) and left circumflex proximal(LCX-pro). Nonparametric analyses were conducted for the comparison. Results:The acquisition time decreased 96.51% in TFE-EPI compared with TFE [(16.3±2.2)s vs.(466.9±101.3)s, t=21.49, P<0.01]. There was no statistical significance in SNR comparison in all the vessel evaluation (all the P>0.05). TFE-EPI showed better CNR in RCA-mid than TFE ( Z=2.65, P=0.008). TFE-EPI showed less image artifacts and distortion in RCA-mid than TFE ( Z=2.00, P=0.046). TFE-EPI also showed better vessel acuity in both RCA-pro and RCA-mid than TFE ( Z=3.88, P<0.001; Z=3.42, P=0.001). Conclusion:Single breath-hold TFE-EPI could greatly shorten scan time while ensuring image quality in coronal artery imaging and has a broad application in future.

Objective:To analyze the detection and influencing factors of work-related musculoskeletal disorders (WMSDs) of workers in an automobile manufacturing enterprise in Guangzhou City.Methods:In April 2020, a total of 7065 workers of an automobile manufacturing enterprise in Guangzhou City were selected as research subjects using cluster sampling method. The Nordic Musculoskeletal Questionnaire (NMQ) was used to investigate the detection of WMSDs. Multiple logistic regression analysis was used to analyze the influencing factors of WMSDs.Results:The detection rate of WMSDs was 43.9% (3102/7065) , among which the detection rate of multiple WMSDs was 31.4%. The detection rates of WMSDs in different parts from high to low were as follows: neck (24.5%) , shoulder (21.1%) and ankle (20.1%) . Multivariate logistic regression analysis showed that working experience of 3-8 years, >8 years, age>30 years old, repetitive work every day, multiple repetitions per minute, uncomfortable work posture, frequent overtime work and lack of staff in the department were risk factors for multi-site WMSDs ( P<0.05) . Adequate rest time was a protective factor for multi-site WMSDs ( P<0.05) . Conclusion:The detection rates of WMSDs in neck, shoulder, ankle, and multisite in automobile manufacturing enterprise are relatively high. The primary risk factors include adverse ergonomic factors and unreasonable organization of labour factors, optimize the work breaks can effectively reduce the risk of disease, effective ergonomic interventions should be carried out to prevent the occurrence of WMSDs among workers in the automobile manufacturing industry.

Objective:To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in the cabinet factory workers, and explore the influencing factors of workers' WMSDs.Methods:A cross-sectional survey method was used to investigate the risk factors such as basic conditions, labox dnganiza, ergonomics load and occurrence of WMSDs of 821 workers in a cabinet factory of a furniture manufacturing company in Guangdong Province using the electronic version of the Musculoskeletal Injury Questionnaire from October to December 2019. χ 2 test and logistic regression were used to analyze the risk factors leading to WMSDs. Results:The incidence of WMSDs in cabinet production workers reached 51.5% (423/821) , and the top three incidences were shoulder (28.4%, 233/821) , neck (28.1%, 231/821) , and wrist (25.9%, 213/821) . The incidence of neck WMSDs was statistically significant among different types of work ( P<0.05) . Multiple repetitive operations per minute ( OR=1.70) , torso often maintaining the same posture ( OR=1.61) , turning heads for a long time ( OR=1.58) and frequent heavy lifting ( OR=1.44) were risk factors for the occurrence of shoulder WMSDs ( P<0.05) . Frequent maintenance of the same posture in the neck ( OR=1.91) , repeated operations per minute ( OR=1.87) , shortage of department staff ( OR=1.65) and turning head for a long time ( OR=1.48) were risk factors for the occurrence of neck WMSDs ( P<0.05) . Long-term bending of the wrist ( OR=2.25) , grasping objects tightly ( OR=2.13) , working hard on the upper limbs or hands ( OR=1.91) , shortage of department personnel ( OR=1.84) , repeated operations per minute ( OR=1.68) and the use of vibration tools ( OR=1.51) were risk factors for the occurrence of WMSDs in the wrist ( P<0.05) . Conclusion:The incidence of WMSDs in cabinet factory is relatively high, the occurrence of WMSDs in the shoulders, necks and wrists is more serious. Reasonable labor organization and reducing the load of poor ergonomics in the workplace, can reduce the occurrence of WMSDs in production workers.

Objective:To analyze the detection and influencing factors of work-related musculoskeletal disorders (WMSDs) of workers in an automobile manufacturing enterprise in Guangzhou City.Methods:In April 2020, a total of 7065 workers of an automobile manufacturing enterprise in Guangzhou City were selected as research subjects using cluster sampling method. The Nordic Musculoskeletal Questionnaire (NMQ) was used to investigate the detection of WMSDs. Multiple logistic regression analysis was used to analyze the influencing factors of WMSDs.Results:The detection rate of WMSDs was 43.9% (3102/7065) , among which the detection rate of multiple WMSDs was 31.4%. The detection rates of WMSDs in different parts from high to low were as follows: neck (24.5%) , shoulder (21.1%) and ankle (20.1%) . Multivariate logistic regression analysis showed that working experience of 3-8 years, >8 years, age>30 years old, repetitive work every day, multiple repetitions per minute, uncomfortable work posture, frequent overtime work and lack of staff in the department were risk factors for multi-site WMSDs ( P<0.05) . Adequate rest time was a protective factor for multi-site WMSDs ( P<0.05) . Conclusion:The detection rates of WMSDs in neck, shoulder, ankle, and multisite in automobile manufacturing enterprise are relatively high. The primary risk factors include adverse ergonomic factors and unreasonable organization of labour factors, optimize the work breaks can effectively reduce the risk of disease, effective ergonomic interventions should be carried out to prevent the occurrence of WMSDs among workers in the automobile manufacturing industry.