ABSTRACT
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.
ABSTRACT
OBJECTIVE: To assess the effect of ergonomic factor load on work-related musculoskeletal disorders(WMSDs) in shipyard workers. METHODS: A total of 751 shipyard workers were selected as the research subjects using judgment sampling method. The exposure level of adverse ergonomic factors was assessed using the Quick Exposure Check method. The prevalence of WMSDs was investigated using the revised Musculoskeletal Disorders Investigating Questionnaire of our research group, and the relationship between them was analyzed. RESULTS: The proportions of high or very high level of work load exposure to the neck, back, shoulder and hand in shipyard workers from high to low were 66.4%, 63.5%, 59.8% and 43.7%(P<0.01) respectively. The proportions of occupational stress, driving, vibration and working rhythm at high or very high exposure level were 20.0%, 4.1%, 22.9% and 3.2%, respectively. The prevalence of WMSDs in four body parts of shipyard workers from high to low was the back, neck, hand and shoulder(the prevalence were 44.2%, 31.2%, 26.9% and 26.6%, respectively, P<0.01). After excluding the influence of confounding factors, multiple logistic regression analysis showed that the higher the labor load exposure level and longer of the vibration tool using, the higher the risk of shoulder WMSDs [odds ratio(OR) and 95% confidence interval(CI) were 1.25(1.04-1.51) and 1.33(1.05-1.69), respectively, P<0.05]. The higher the level of occupational stress, the higher the risk of back and neck WMSDs [OR(95%CI) was 1.29(1.05-1.58) and 1.42(1.15-1.77), respectively, P<0.05]. CONCLUSION: There was a dose-effect relationship between the exposure level of shoulder load, the time of using vibration tools and the shoulder WMSDs, and there was a dose-effect relationship between the occupational stress level and the WMSDs in the back and neck.
ABSTRACT
OBJECTIVE: To analyze the relationship between the blood biochemical indexes and the local muscle fatigue of operators with local muscle fatigue caused by moderate-load repetitive manual lifting. METHODS: Five healthy male volunteers were selected as the research subjects. They repeatedly performed simulated manual lifting operation for four periods(T1-T4), 10 minutes per period. Each period was suspended for 3 minutes to be accessed for the rating of perceived exertion(RPE) score of local muscle. Meanwhile, their venous blood was collected to be detected for serum calcium ion, creatine kinase, cartilage oligomeric matrix protein(COMP), ammonia, lactic acid, lactate dehydrogenase(LDH), C-reactive protein(CRP), and collagen type Ⅱ C terminal telopeptide(CTX-Ⅱ). RESULTS: The RPE score and serum creatine kinase level of the subjects increased with the increasing of lifting time(P<0.05). Serum calcium ion levels in time periods T2, T3 and T4 were higher than that in T1(P<0.05). Serum COMP levels in T3 and T4 were higher than that in T1(P<0.05). The levels of ammonia,lactic acid, LDH, CRP and CTX-Ⅱ in each time period showed no statistical significance(P>0.05). Serum creatine kinase, calcium ion and LDH levels were positively correlated with RPE score(correlation coefficient were 0.840, 0.512, 0.741, respectively, P<0.01). CONCLUSION: Serum creatine kinase is a sensitive, effective and objective index reflecting muscle fatigue, which is suitable for evaluating the fatigue process of moderate-load repetitive activities. Serum calcium ion has a good correlation with muscle fatigue, and serum COMP can reflect muscle fatigue to some extent.
