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Journal of Environmental and Occupational Medicine.2023;40(1):1-5. doi:10.11836/JEOM22502

Work-related musculoskeletal disorders (WMSDs) are chronic and cumulative disorders that are affected by multiple ergonomic factors. They are widespread in occupational populations and have a high prevalence. They have caused a substantial economic and social burden, which has become a major occupational health problem worldwide. The mechanism of WMSDs needs to be clarified. More authoritative and unified diagnostic criteria and specific therapeutic drugs are required. Therefore, an in-depth epidemiological investigation on WMSDs involving occupational ergonomics is of great scientific value and practical significance, which aims to improve hazard identification and ergonomic load risk assessment and to facilitate the prevention, control, and intervention of WMSDs. This article introduced the concept, status report, risk factors, ergonomic assessment methods, and preventive measures of WMSDs. This special column on "occupational ergonomics and work-related musculoskeletal disorders" presented the prevalence and related risk factors of WMSDs in different industries, as well as working condition simulation studies for specific tasks, aiming to provide objective and detailed scientific data for the prevention and control of WMSDs.

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Jiancheng ZENG ; Yan YANG ; Siwu ZHONG ; Yimin LIU ; Zhongxu WANG ; Ning JIA ; Zhi WANG

Journal of Environmental and Occupational Medicine.2023;40(1):6-12. doi:10.11836/JEOM22299

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.

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Prevalence and influencing factors of work-related musculoskeletal disorders among workers in chemical pharmaceutical industry

Zhiheng PENG ; Weiyu MA ; Yinan HE ; Bo LUO ; Jinlan HUANG ; Hai ZHANG ; Jinwei ZHANG ; Zhongxu WANG ; Ning JIA ; Zhi WANG

Journal of Environmental and Occupational Medicine.2023;40(1):13-20. doi:10.11836/JEOM22265

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.

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Prevalence of work-related musculoskeletal disorders and its influencing factors among workers involving climbing task in power supply enterprises

Dan ZHANG ; Baoyu ZHU ; Zhanhui LIANG ; Tao CHEN ; Hongyan LI ; Yang GAO ; Jiajie LI ; Qingsong CHEN

Journal of Environmental and Occupational Medicine.2023;40(1):21-26. doi:10.11836/JEOM22302

Background Operation and maintenance work in the power grid industry often involving climbing, manual handling, and poor postures causing serious problems like work-related musculoskeletal disorders (WMSDs). The influencing factors of WMSDs are not very clear, but the problem has been widely concerned in this industry. Objective To understand the prevalence and influencing factors of WMSDs among climbing task-involved workers in power supply enterprises. Methods Using a cross-sectional design, a total of 702 workers involving climbing task from 10 power supply enterprises in Jilin Province, Tianjin Municipality, and Shandong province were selected as study subjects using cluster sampling. The Musculoskeletal Disorders Questionnaire which was revised by Lei Yang was used to estimate the prevalence and identify related factors of WMSDs.

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test and multiple logistic regression were used to analyze the data. Results A total of 702 subjects were approached, 649 valid questionnaires were recovered, and the effective recovery rate was 92.45%. The prevalence of WMSDs was 81.2%, and neck (65.0%), low back (59.0%), and shoulders (54.4%) were areas of high prevalence of WMSDs. The multiple logistic regression analysis results showed that sometimes and often/very often holding awkward postures were the risk factors of neck, shoulders, low back, knees, upper back, hands/wrists, ankles/feet, elbows, and hips/thighs WMSDs; the OR (95%CI) values were 1.931 (1.260-2.959) and 3.145 (1.810-15.465), 2.700 (1.694-4.305) and 3.888 (2.224-6.798), 1.860 (1.213-2.852) and 3.150 (1.833-5.414), 2.348 (1.456-3.785) and 3.689 (2.130-6.388), 1.782 (1.128-2.815) and 3.274 (1.935-5.538), 1.710 (1.014-2.884) and 2.595 (1.455-4.630), 1.836 (1.019-3.305) and 2.860 (1.526-5.358), 2.250 (1.185-4.275) and 3.032 (1.505-6.108), 2.080 (1.048-4.128) and 3.127 (1.501-6.516), respectively. Department staff shortage was the risk factor of neck, shoulders, low back, upper back, hands/wrists, and ankles/feet WMSDs; the OR (95%CI) values were 1.791 (1.038-3.093), 2.000 (1.119-3.573), 2.506 (1.429-4.394), 2.063 (1.113-3.822), 2.256 (1.069-4.762), and 2.699 (1.103-6.601), respectively. Frequent knee bending was the risk factor of knees, upper back, and hands/wrists WMSDs; the OR (95%CI) values were 1.895 (1.327-2.704), 1.586 (1.131-2.224), and 2.026 (1.390-2.951), respectively. Often pushing/pulling heavy objects was the risk factor of shoulders, low back, and hips/thighs WMSDs; the OR (95%CI) values were 1.485 (1.066-2.192), 1.547 (1.064-2.749), and 1.822 (1.160-2.862), respectively. Long-time heavily neck tilting forward was the risk factor of elbows and hips/thighs WMSDs; the OR (95%CI) values were 1.649 (1.068-2.546) and 2.005 (1.285-3.129) respectively. Long-time ankle or foot bending was the risk factor of ankles/feet and elbows WMSDs; the OR (95%CI) values were 2.481 (1.685-3.655) and 1.655 (1.065-2.571) respectively. Cold or changes in temperature was the risk factor of neck and shoulders WMSDs; the OR (95%CI) values were 2.182 (1.072-4.443) and 2.116 (1.010-4.431) respectively. Exercise was the protective factor of neck, shoulders, low back, upper back, and ankles/feet WMSDs; the OR (95%CI) values were 0.493 (0.363-0.666), 0.625 (0.438-0.888), 0.404 (0.283-0.576), 0.570 (0.408-0.797), and 0.639 (0.436-0.937), respectively. Conclusion The prevalence of WMSDs is high among workers involving climbing task in power supply enterprises, and neck, low back, and shoulders are the most commonly affected body parts. The influencing factors involve awkward postures, repetitive movements, repetitive tasks, pushing/pulling heavy objects, staff shortage, poor working environment, and exercise.

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Influencing factors and prediction model of neck pain in dentists

Peifang LIU ; Bo SHEN ; Xuyan XU ; Jianhua LIU ; Wenli CHEN ; Sihao LIN

Journal of Environmental and Occupational Medicine.2023;40(1):27-33. doi:10.11836/JEOM22289

Background Dentists are a high-risk population of work-related musculoskeletal disorders (WMSDs), where the body part with the highest prevalence is the neck. Objective To analyze potential influencing factors of neck pain among dentists, and explore a prediction model of neck pain in dentists. Methods Dentists from different hospitals in Fuzhou were selected as study subjects by stratified cluster sampling according to hospital characteristics (dental hospitals, general hospitals, and dental clinics). The basic information, presentation of WMSDs, and its influencing factors were investigated by using the Chinese version of Musculoskeletal Disorders Questionnaire and the Subjective Workload Assessment Technique. A total of 655 questionnaires were collected, of which 603 were valid, with an effective rate of 92.1%. Multiple logistic regression was used to analyze potential influencing factors of neck pain in dentists. A prediction model of neck pain of dentists was constructed by using neural network model, and the prediction efficiency of the model was evaluated. Results The neck was the body part with the highest prevalence (43.8%, 264/603) of WMSDs among dentists. The results of multiple logistic regression analysis showed that female (OR=2.709, 95%CI: 1.852-3.962, P <0.001), working age of 10-<20 years (versus <10 years, OR=3.836, 95%CI: 2.471-5.957, P<0.001), keeping head up or down for a long time (OR=8.492, 95%CI: 2.203-32.731, P=0.002), holding head sideways for a long time (OR=2.210, 95%CI: 1.376-3.550, P<0.001), maintaining the same sitting spot for a long time (OR=4.336, 95%CI: 2.192-8.579, P<0.001), and psychological load value ≥70 (versus <40, OR=1.901, 95%CI: 1.038-3.480, P=0.037) increased the risk of neck pain in dentists. Sufficient operating space (OR=0.507, 95%CI: 0.302-0.850, P=0.010) and doing some exercise during work break (OR=0.670, 95%CI: 0.453-0.991, P=0.045) reduced the risk of reporting neck pain among dentists. A neural network prediction model of dentists' neck pain was constructed with 1 hidden layer and 6 hidden layer neurons. The percentage of correct prediction of training set was 89.6%, and the percentage of correct prediction of test set was 83.9%. The order of importance of the independent variables included in the model were working age, holding head sideways for a long time, psychological load, etc. The result of neural network model of neck pain among dentists showed that the area under the curve of receiver operator characteristic (ROC) was 0.940 (95%CI: 0.922-0.958, P<0.001). When the maximum diagnostic value was determined by the ROC curve, the sensitivity was 84.8%, the specificity was 91.2%, and the Youden Index was 0.760. Conclusion Neck pain of dentists is affected by many factors, such as individual factors (gender and working age), ergonomic factors (keeping various postures and operations for a long time, operating space, etc.), psychological factors (different levels of psychological load) and so on. The neural network model can be used as a prediction tool to explore the risk of reporting neck pain among dentists.

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Neck and shoulder pain among operation and maintenance workers of selected power supply enterprises

Dan ZHANG ; Baoyu ZHU ; Jiajie LI ; Hongyan LI ; Yang GAO ; Zhanhui LIANG ; Qingsong CHEN

Journal of Environmental and Occupational Medicine.2023;40(1):34-42. doi:10.11836/JEOM22345

Background Power grid is a basic industry of national economy. The occupational health problems among operation and maintenance workers in this industry have become increasingly prominent in recent years, and they should receive enough attention. Objective To estimate the prevalence of work-related musculoskeletal disorders (WMSDs) of neck and shoulder among operation and maintenance workers of power supply enterprises, and analyze related influencing factors. Methods From March to June 2021, a total of 1433 operation and maintenance worker from 10 power supply enterprises in three provinces of North China were selected as research subjects using cluster sampling method. A revised Musculoskeletal Disorders Questionnaire was used to investigate the prevalence and ergonomic factors of neck and shoulder pain in the past year. χ² test and logistic regression model were used to explore influencing factors of neck and shoulder pain among operation and maintenance workers. Results A total of 1343 valid questionnaires were recovered and the effective recovery rate was 93.72%. The neck pain prevalence was 66.0% (886 cases) and the shoulder pain prevalence was 54.1% (727 cases). The multiple logistic regression analysis results showed that often/very often long-time sitting (OR=1.864, 95%CI: 1.236-2.811; OR=1.659, 95%CI: 1.091-2.524), sometimes holding awkward postures (OR=1.695, 95%CI: 1.294-2.219; OR=1.596, 95%CI: 1.218-2.092), often/very often holding awkward postures (OR=2.416, 95%CI: 1.618-3.607; OR=2.058, 95%CI: 1.405-3.015), long-time slight neck tilting forward (OR=1.327, 95%CI: 1.023-1.722; OR=1.571, 95%CI: 1.221-2.022), long-time elbows bending (OR=1.327, 95%CI: 1.023-1.722; OR=1.506, 95%CI: 1.112-2.040) and department or team staff shortages (OR=1.578, 95%CI: 1.153-2.161; OR=1.831, 95%CI: 1.320-2.539) were associated with higher neck and shoulder pain prevalence rates. While exercise (OR=0.630, 95%CI: 0.492-0.809; OR=0.707, 95%CI: 0.557-0.899) was associated with lower neck and shoulder pain prevalence rates. Doing same work every day (OR=1.704, 95%CI: 1.305-2.225) was associated with a higher neck pain prevalence rate. Awkward postures with ineffectual force (OR=1.808, 95%CI: 1.226-2.665) and often keeping arms above shoulders (OR=1.424, 95%CI: 1.017-1.992) were associated with a higher shoulder pain prevalence rate. Conclusion The prevalence rates of neck and shoulder pian are high among operation and maintenance workers of power supply enterprises in selected three provinces of North China, and the main associated factors include individual factors, awkward work postures, and labor organization.

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Influencing factors and attribution analysis of hand/wrist musculoskeletal disorders among welders in an automobile factory

Zheng LI ; Jiabing WU ; Guobing ZHAO ; Hong YIN

Journal of Environmental and Occupational Medicine.2023;40(1):43-48. doi:10.11836/JEOM22308

Background Welders in automobile manufacturers are prone to hand/wrist musculoskeletal disorders (MSDs), which seriously affect workers' physical and mental health. Objective To investigate the factors influencing hand/wrist MSDs of welders in an automobile factory and the population attributable risk percentage (PARP). Methods Five branches of an automobile factory were selected by convenient sampling method, and all qualified welders in the selected branches were enrolled as research participants. The Chinese Musculoskeletal Disorders Questionnaire was used to collect information such as general characteristics of welders, presentation of MSDs in the wrists and hands, and selected ergonomic factors. Log-binomial model in the SAS program was used to calculate the prevalence ratio (PR) of each influencing factor and PARP. Results The prevalence rate of MSDs in the hands/wrists of welders in the automobile factory was 44.1% (345/782). The results of multiple analysis showed that female (PR=1.25, 95%CI: 1.10-1.44), being very tired after work (versus not tired, PR=2.22, 95%CI: 1.16-4.25), twisting wrists (PR=1.44, 95%CI: 1.19-1.74), insufficient operating space (PR=1.22, 95%CI: 1.07-1.40), and holding or pinching objects by hands (PR=1.58, 95%CI: 1.18-2.12) increased the risk of reporting hand/wrist MSDs symptoms. The PARP of major occupational risk factors was: holding or pinching objects by hands, 32.46%; twisting wrists, 21.50%; being very tired after work, 15.28%; and insufficient operating space, 8.18%. Conclusion The prevalence of MSDs symptoms in hands/wrists of welders in this automobile factory is high. Gender, holding or pinching objects by hands, twisting wrists, being very tired after work, and insufficient operating space are the factors affecting hand/wrist MSDs, among which holding or pinching objects by hands and twisting wrists are the priority intervention factors.

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Association between wrist pain and awkward postures among workers in 10 key industries

Guanlin LI ; Xin SUN ; Meibian ZHANG ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Gang LI ; Nengzhou CHEN ; Zaoliang REN ; Yan YIN ; Hua SHAO ; Hengdong ZHANG ; Jiajie LI ; Bing QIU ; Dayu WANG ; Qiang ZENG ; Zhanhui LIANG ; Rugang WANG ; Jianchao CHEN ; Danying ZHANG ; Liangying MEI ; Yongquan LIU ; Jixiang LIU ; Chengyun ZHANG ; Tianlai LI ; Ning JIA ; Junyi WANG ; Zhongxu WANG ; Qingsong CHEN

Journal of Environmental and Occupational Medicine.2023;40(1):49-54. doi:10.11836/JEOM22298

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.

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Effect of long working hours on work-related musculoskeletal disorders among operation and maintenance workers of power supply enterprises

Baoyu ZHU ; Dan ZHANG ; Zhanhui LIANG ; Yang GAO ; Hongyan LI ; Jiajie LI ; Qingsong CHEN

Journal of Environmental and Occupational Medicine.2023;40(1):55-61. doi:10.11836/JEOM22342

Background Long working hours is harmful to the physical and mental health of occupational groups, and should receive active attention. Objective To evaluate the current status of long working hours among operation and maintenance workers of power supply enterprises, and explore its effects on work-related musculoskeletal disorders (WMSDs) of the population. Methods From March to June 2021, a cross-sectional survey was conducted among 1433 operation and maintenance workers from 10 power supply enterprises in Jilin Province, Shandong Province, and Tianjin Municipality using cluster sampling. A total of 1433 copies of revised Mus-culoskeletal Disorders Questionnaire were distributed, 1343 questionnaires were recovered, and the recovery rate was 93.72%. The questionnaire included general information, personal health behaviors, weekly working hours, work-related factors, and musculoskeletal pain or discomfort in nine body parts in the past 12 months. χ² test and multiple logistic regression models were used to investigate the relationships between long working hours (>40 h per week) and WMSDs. Results The average age of the workers was (39.42±9.89) years, and the average work experience was 11.00 (5.00, 21.00) years. There were 1158 males (86.22%) and 185 females (13.78%). The average weekly working hours of the workers were (47.98±11.35) h, and the proportion of long working hours (>40 h per week) was 61.06% (820/1343). The proportions of long working hours were higher among the workers with characteristics of male, power distribution, shift work, often/very often long-time standing, often/very often holding awkward postures, often handling heavy objects, limited space to operate, long-time neck tilting backward, keeping arms above shoulders, frequent elbow bending, repeating knee movement every minute, and repeating lower limb or foot movement every minute (all P<0.05). The prevalence rate of WMSDs was 81.53% (1095/1343) among the workers. The results of multiple logistic regression showed that after adjusting education, smoking, exercise, awkward postures, often handling heavy objects, limited space to operate, long-time heavy trunk bending, long-time neck tilting backward, and keeping arms above shoulders, compared with working ≤40 h per week, the risk of WMSDs among workers working >49 h per week was higher (OR=1.406, 95%CI: 1.011-1.955). Conclusion Long working hours is prominent among operation and maintenance workers of power supply enterprises, and increases the risk of reporting WMSDs.

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Local muscle load and fatigue of simulated high-voltage cable climbing task of operation inspection personnel by surface electromyography

Zhanhui LIANG ; Jiajie LI ; Dan ZHANG ; Baoyu ZHU ; Hongyan LI ; Yang GAO ; Qingsong CHEN

Journal of Environmental and Occupational Medicine.2023;40(1):62-67. doi:10.11836/JEOM22301

Background Climbing pylons during high-voltage cable maintenance is not only a labor-intensive task, but also a challenge bringing about heat stress and mental pressure from working at height, which may lead to accumulation of muscle fatigue and work-related musculoskeletal disorders. Objective To record the local muscle fatigue during a simulated climbing task by high-voltage cable electricians based on surface electromyography (sEMG) signals, explore the characteristic changes in sEMG signals and their relationship with subjective fatigue evaluation of the task, and provide data support for developing task specific objective assessment tools for local muscle fatigue and prevention of work-related musculoskeletal disorders. Methods Ten male college students were recruited to conduct a test of a simulated pylon climbing task. The climbing distance was 60 m, and a task segment was set for every 20 m (about 100 s), recorded as T1, T2, and T3, respectively. After completing each task segment, the subjects were required to rate their subjective fatigue using the Borg's RPE Scale. Fatigue was defined by rating of perceived exertion (RPE) score ≥ 14 in this study. The sEMG signals of trapezius, erector spinae, rectus femoris, and gastrocnemius muscles were recorded wirelessly. The standardized maximal voluntary electrical activation (MVE) obtained by standardizing the root mean square (RMS) of the time domain index and the median frequency (MF) of the frequency domain index were estimated for the recorded sEMG signals, and joint amplitude and spectrum analysis (JASA) was used to evaluate local muscle fatigue of target muscles involving in the climbing task. Results The RPE scores of T1, T2, and T3 were 11.9, 15.3, and 17.4, respectively. Subjective fatigue was found in T2 and T3 but not in T1. With the extension of climbing time, the MVE values of left and right erector spinae muscles, left and right rectus femoris, and right gastrocnemius muscle increased gradually, while the MVE values of left and right trapezius muscles and left gastrocnemius muscle increased first and then decreased. The MF values of left and right rectus femoris increased at first, then remained unchanged, while the MF values of the other muscles remained basically unchanged. In T1, three muscles, including left trapezius muscle and both side of erector spinae muscles, showed fatigue; in T2, five muscles, including both sides of erector spina muscles, right trapezius muscle, and both sides of gastrocnemius muscle appeared fatigue; in T3 , except for left rectus femoris, the other seven muscles were fatigue. Conclusion The characteristic changes of electromyography signals in the simulated climbing task are not completely consistent with the typical amplitude increase and left shift of the frequency spectrum of sEMG signals in static tasks, indicating that the application of time-domain and frequency-domain analysis methods in the evaluation of muscle fatigue in climbing tasks needs further discussion. Trapezius muscles and erector spinae muscles are the first to show fatigue in the simulation, and may be the sensitive muscle groups of muscle fatigue associated with climbing movement. Compared with subjective evaluation, surface electromyography is more sensitive in the assessment of body fatigue. Fatigue is reported about 100 s of climbing (the climbing length is about 20 m).

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