Risk assessments of work-related musculoskeletal disorders among the TFT-LCD manufacturing operators

The thin film transistor liquid crystal display (TFT-LCD) industry is one of the major industries in Taiwan, yet few studies addressed its work-related musculoskeletal disorders (WMSDs). Thus, this study aims to evaluate the risk of WMSDs among the operators of a TFT-LCD manufacturing company in Taiwan by using the subjective questionnaire and ergonomic assessment tools. First, the NMQ survey was conducted among 393 operators, accounting for 94% of all operators in the TFT-LCD plant. The results showed that the prevalence of WMSDs was 31.8%. Among the various body parts, the highest prevalence of WMSDs was found in neck and shoulders (20.4%), while upper limbs were with the lowest prevalence (9.2%). Besides, the prevalence of WMSDs tends to be affected by both work factors and operator factors. Those who were more experienced, working in day shift and involved in the Array process tend to have a higher prevalence of WMSDs. Further, female and domestic operators reported a higher prevalence of WMSDs than male and foreign operators. Moreover, the jobs of 50 employees were analyzed using ergonomic assessment tools including OSHA MSDs, BRIEF, OWAS, 3D SSPP, and NIOSH lifting equation. The findings indicated that inadequate working height, restricted working space, awkward postures, overweight load, and high repetition were the major risk factors of WMSDs. Thus, countermeasures such as redesigning the workstations and material handling carts, proactive training of manual material handling, and providing safety clearance are recommended to enhance the occupational health and safety of the TFT-LCD operators.     

A toolkit for the analysis of biomechanical overload and prevention of WMSDs: Criteria,procedures and tool selection in a step-by-step approach

BackgroundWhen studying work related musculoskeletal disorders (WMSDs), various factors (mechanical, organizational, psychophysical, individual) and their interrelationships have been considered to be important in general models for epidemiologic surveys and risk assessment and management. Hence the need for a “holistic” approach towards MSD prevention. On the other hand, considering the widespread presence of these factors and of WMSDs in many work places located in both developed and developing countries, there is a strong demand from OSH agencies and operators for “simple” risk assessment and management tools that can also be used by non-experts.ObjectivesThis paper is one of the main contributions towards a WHO/IEA project for developing a “Toolkit for WMSD prevention” by the TC on MSD of the IEA. The paper focuses on selecting tools at different levels for hazard identification, risk estimation and management. The proposals were primarily developed in this context but they also derive from other converging issues such as the ISO TR 12295 – published in 2014.Methods and criteriaProposals are based on two essential criteria: 1) adoption of a step-by-step approach starting with basic tools and moving to more complex tools only when necessary; 2) factoring in complexity and the presence of multiple influencing factors at every step (although with different degrees of in-depth analysis).ResultsThe proposals include: Step one: identification of preliminary occupational hazards and priority setting via “key-enter” questions (at this step, all potential hazards affecting WMSDs should be considered). Step two: identification of risk factors for WMSDs, consisting of a “quick assessment” and substantially aimed at identifying three possible conditions: acceptable/no consequences; critical/redesign urgently needed; more detailed analysis required. Step three: recognized tools for estimating risk (of WMSDs) are used depending on the outcomes of step two. Examples of such tools include “adaptations” of the Revised NIOSH Lifting Equation, Liberty Mutual Psychophysical Tables, OCRA Checklist, etc. These tools should adequately cover most of the influencing factors.Relevance to industryThe use of a step-by-step approach and validated risk estimation tools, in accordance with international standards, makes it possible to tackle the challenge of simplifying complexity in the assessment of biomechanical overload conditions and in the prevention of WMSDs in enterprises of all sizes, small businesses, agriculture, and in developing countries.     

Investigation of oil palm harvesting tools design and technique on work-related musculoskeletal disorders of the upper body

The oil palm industry is one of the important sectors in Malaysia. The growth and development of this industry shows that Malaysia is the world second-largest oil palm producers. However, in the fresh fruit bunch (FFB) harvesting process, the harvesters are exposed to many types of work-related musculoskeletal disorders (WMSDs). The FFB harvesters tend to develop WMSDs especially the shoulders and trunk. Hence, it is important to identify the exposure levels, awkward postures and the reaction forces of muscle activity based on the posture and movement of the harvesters when using pole, chisel and loading spike during the harvesting process. The objective of this study was to investigate the effect of the design of oil palm FFB harvesting tools on WMSDs of the upper body. Rapid Upper Limb Analysis (RULA) was used to investigate and assess the exposure level on the harvester body during the harvesting process. The assessment showed that the shoulders and trunk have high exposure level and undergo awkward posture. Human Musculoskeletal Model Analysis (HMMA) was used to identify the reaction force exerted on the muscle during the FFB harvesting process. In this study, 4 muscles were analysed including Triceps, Biceps, Erector Spinae and Psoas Major. The highest reaction force of 16.36 N was found on the left triceps when handling a loading spike. In conclusion, it is important to address the risks by reviewing all possible aspects that contribute to the WMSDs and interventions on the tool design, task and working shifts may be required.     

Analysis of the return on preventive measures in musculoskeletal disorders through the benefit–cost ratio: A case study in a hospital

Work-related musculoskeletal disorders (WMSDs) are among the most costly health problems that society is facing today. Prevention involves investments and it is important for organizations to make a cost–benefit analysis of ergonomic projects. Return on prevention is a recent concern in the domain of occupational safety and health (OSH). There are many studies concerning the return on the prevention of WMSDs, in terms of the benefits for the organization in which the preventive measures are implemented. However, it is also important to perform an analysis of the impact of each measure on society (externalities). A model to perform a financial and economic cost–benefit analysis related to OSH projects was developed and it was applied in the case of the prevention of WMSDs in a Portuguese hospital. An analysis of the accidents and corresponding costs has been made in six of the services of the hospital. Financial and an economic cost–benefit analysis have been made and the benefit–cost ratio (B/C) has been calculated. While the B/C financial ratio, considering only the benefits to the hospital, is around 2, the economic B/C ratio, taking into account all the external benefits that have been quantified, is higher than 14.Relevance to industryBoth the economic and the financial B/C ratio are important support tools for decision makers in public and private organizations, helping them to define which preventive measures should be implemented, taking into account the costs involved and the resulting quantified benefits, for the organization, for the workers and for the society.     

Deep learning-based classification of work-related physical load levels in construction

Work-related musculoskeletal disorders (WMSDs) are the leading cause of the nonfatal injuries for construction workers, and a worker’s overexertion is a major source of such WMSDs. Pushing, pulling, and carrying movements—which are all activities largely associated with physical loads—account for 35% of WMSDs. However, most previous studies have focused on the identification of non-ergonomic postures, and there has been limited effort expended on measuring a worker’s exposures to the physical loads caused by materials or tools during construction tasks. With the advantage of using a wearable inertial measurement sensor to monitor a worker’s bodily movements, this study investigates the feasibility of identifying various physical loading conditions by analyzing a worker’s lower body movements. In the experiment with laboratory settings, workers performed a load carrying task by moving concrete bricks. A bidirectional long short-term memory algorithm is employed to classify physical load levels; this approach achieved 74.6 to 98.6% accuracy and 0.59 to 0.99 F-score in classification. The results demonstrate the feasibility of the proposed approach in identifying the states of physical loads. The findings of this study contribute to the literature on classifying ergonomically at-risk workers and on preventing WMSDs in high physical demand occupations, thereby helping enhance the health and safety of the construction workplace.     

Analysis of worker strategies: A comprehensive understanding for the prevention of work related musculoskeletal disorders

By documenting the strategies developed by food processing workers to manage their musculoskeletal pain and discomfort in order to remain on the job, the present article seeks to increase awareness of a different “way of approaching” WMSDs inspired by the ergonomic approach centred on work activity analysis. Based on a mixed methods approach, an ergonomic work activity study combined with a multiple case study was conducted. Sixteen female seafood-processing workers were followed up during two consecutive work seasons using a range of interviews as well as observations of work activity throughout the entire study. A large variety of musculoskeletal pain management strategies developed by those workers to remain on the job were identified. This identification and the process of categorizing the strategies led to the development of a framework for studying worker strategies. The mixed methods approach made it possible to better pinpoint and understand obstacles to the development of workplace strategies and then identify avenues for change to improve working conditions.Relevance to industryThe framework constitutes a valuable contribution for the prevention of WMSDs by representing a methodological tool for documenting worker strategies. Very few tools of this kind are currently available for practitioners and researchers. In becoming aware of the existence of such coping strategies, companies can gain a better understanding of the difficulties workers have to cope with.     

The investigation of work-related musculoskeletal disorders among female workers in a hazelnut factory: Prevalence,working posture,work-related and psychosocial factors

BackgroundWork-related musculoskeletal disorders (WMSDs) are the most common occupational health problems in the industrialized world. The identification of WMSDs specific to occupation is essential to plan and implement preventative programs. This study investigated the prevalence of WMSDs and determined the factors related to the severity of the most common disorders among female workers in a hazelnut factory.MethodsA total of 114 female workers were examined in this cross-sectional study using the Nordic Musculoskeletal Questionnaire, the Dutch Musculoskeletal Questionnaire, and an author-developed questionnaire (for socio-demographic characteristics and psychosocial factors). Working posture, craniovertebral angle, thoracic kyphosis angle (TKA), and lumbar lordosis angle were evaluated based on a photogrammetry method using the ImageJ program.ResultsThe prevalence of WMSDs in at least one body part during the last 12 months was 92.1%. The highest prevalence of WMSDs was in the lower back (61.4%), neck (57.9%), shoulder (53.6%), and upper back (45.6%). The least affected part was the elbow. Lower back, shoulder, and neck disorders were the most common causes of activity limitation. The severity of lower back pain was associated with stress in the workplace and work-related factors. The neck pain severity was related to craniovertebral angle and work-related factors. The shoulder pain severity increased with TKA and employment duration. TKA was related to upper back pain severity.ConclusionsWMSDs are common among female workers in a hazelnut factory. Reorganizing of working posture, work-related factors, and stress at work may be beneficial to decrease the prevalence of WMSDs and pain severity.Relevance to Industry; The female workers in the hazelnut factory are vulnerable to the work-related musculoskeletal disorders, particularly in the spinal region. The employers should endeavor to improve the health of the workers by the adjustment of the working posture and environmental factors.     

Vibration of portable orbital sanders and its impact on the development of work-related musculoskeletal disorders in the furniture industry

The wood furniture industry has a strong presence in Canada, where it employs over 100,000 workers. Because of the extensive number of manual tasks required in this industry, several studies have been undertaken to characterize the health and safety risk factors to which these workers are exposed, such as awkward postures, repetitive movements and the application of undue force. However, very little research has been done on workers’ exposure to vibration from portable orbital sanders, one of the most common tools used in this industry. Vibration is responsible for a specific occupational disease called vibration syndrome, but is also recognized as a risk factor that increases the prevalence of more common work-related musculoskeletal disorders (WMSDs). This study proposed to determine the level of vibration to which sanders of furniture parts are exposed, and to analyze its impact on the risk of WMSDs. The results show that the level of vibration to which the workers are exposed is well above acceptable levels defined by recognized standards and directives and that this vibration is combined with many other risk factors, thus representing a risk for the development of WMSDs.     

Wrist and tendon dynamics as contributory risk factors in work‐related musculoskeletal disorders

Many studies have shown that repetitive wrist motion is a major risk factor for work‐related musculoskeletal disorders (WMSDs). Specific contributory factors include wrist and tendon dynamics. The authors present recent methodological advances, epidemiological studies, and biomechanical models estimating the effects of wrist dynamics on internal tendon force as a theoretical basis for the risk of incurring a WMSD. These biomechanical models utilize either the reduction method or the optimization method to solve the indeterminate problem resulting from too many internal variables. Generally, the optimization methods show the best agreement with direct in vivo tendon force studies. For the models of pinch grips, the average ratio of tendon forces to external forces ranges from 1.8 to 3.5, while for direct tendon measurements, the ratio ranges from 1.73 to 7.92. Similarly, high contributions of flexor tendons for pinches and grasps are found in both the models and direct tendon measurements. These high tendon forces combined with wrist dynamics may be a significant factor in the development of WMSDs. © 2006 Wiley Periodicals, Inc. Hum Factors Man 16: 83–105, 2006.     

Risk factors analysis: Work-related musculoskeletal disorders among male traffic policemen using high-powered motorcycles

IntroductionThe occupational safety and health issues for police riders and other professional riders are often related to ergonomic hazards and risks. The purpose of this research was to identify the factors that contribute to the health effects in developing work-related musculoskeletal disorders (WMSDs) among male traffic policemen using high-powered motorcycles.Materials and methodsA cross-sectional study was conducted using 137 police riders. A set of questionnaires including the Standardised Nordic Questionnaire (SNQ) and human vibration meter (Svantek 106) was used in this study.ResultsThe prevalence of WMSDs was 67.9%. Multiple logistic regression analysis revealed that the duration of riding a motorcycle (OR = 0.175, 95% CI:0.052, 0.581), years of service (OR = 0.152, 95% CI: 0.040, 0.567), and hand-arm vibration, HAV (OR = 3.053, 95% CI: 1.126, 8.280) were significant risk factors for the prevalence of WMSDs.DiscussionThe majority of riders reported symptoms of WMSDs within the past 12 months. Riding duration, years of service, and hand-arm vibration (HAV) were found to be the most important risk factors for WMSDs in this rider group. The results highlight that in the context of ergonomic interaction, high-powered motorcycles and the police riders are not a good fit. Hence, further study is needed to improve the safety and health of the police riders.     

Legal system and its effect for prevention of work-related musculoskeletal disorders in Korea

This study aims to introduce the legislation of occupational safety and health regulations for prevention of WMSDs in Korea and investigate its effect by showing an ergonomic intervention effort in a major motor company. In Korea, WMSDs incidence rates had increased from 1999 to 2003, and it is noted that its increment jumped rapidly in 2002 and 2003. The Korean government established a law prescribing employers’ duty of preventing WMSDs in 2002, which began effective in July, 2003. Following the legislation, all employers should execute the examination of WMSDs risk factors for the eleven designated tasks every three years. In addition to this legal obligation, some large companies voluntarily established an ergonomic intervention program by carrying out in-depth assessments for stressful tasks using OWAS, RULA, NLE, etc. We introduce a major motor company case to illustrate the industry’s activities of fulfilling the legislative requirement and of performing ergonomic assessments. Thanks to Korean government and industry’s effort for prevention of WMSDs, the incidence rates of WMSDs have continually decreased from the year of 2004, right after the year when the WMSDs-related regulation was enforced.

Relevance to industry

In spite of booming of information technology industries and automation of manufacturing processes in Korea, many workers are still exposed to the risk of WMSDs including awkward postures, stressful force exertions, repetitive motions in manufacturing and agriculture industries. WMSDs cases alone constitute 43.1% of occupational diseases in Korea and the industry’s effort of ergonomic intervention of WMSDs becomes a major issue to both the management and the labor union.     

Physical and mental workload interactions in a sterile processing department

Work in healthcare facilities has been categorized as a high-risk job for developing Work-Related Musculoskeletal Disorders (WMSDs). Little attention has been given to the Sterile Processing Department (SPD) employees who are exposed to both mentally and physically demanding conditions, factors that may impose an elevated risk in the development of WMSDs. Previous studies have shown that WMSDs can be a result of complex interactions between physical, psychosocial, biological, and individual characteristics. However, the evidence of specific associations is still inconclusive. The objective of this study was to determine if the perception of mental workload causes workers to adopt more risky body postures. The study was carried out in four phases: 1) identification of musculoskeletal disorders using customized Nordic questionnaires, 2) ergonomic assessment of SPD using REBA method, 3) mental workload assessment of SPD using NASA-TLX, and 4) interaction between physical (postural risk) and mental workload through the performance of a task at two different levels of workload conducted through a controlled experiment. The findings indicate that increases in REBA scores and NASA-TLX indices were associated with days and conditions with higher workloads. Results showed evidence that increments on mental workload are related to worsening postures, increasing the risk of developing musculoskeletal disorders. These results serve to raise awareness and warn employees about the need to pause and analyze the way they perform their duties under high levels of workload in an attempt to reduce WMSDs risk in healthcare sector employees.     

Paddling upstream: a contextual analysis of implementation of a workplace ergonomic policy at a large newspaper

Efforts to implement workplace ergonomic programs aimed at reducing the burden of work-related musculoskeletal disorders (WMSD) have to address multiple physical and psychosocial aspects of work environments yet often contextual factors limit their success. We describe the processes involved in an ergonomic program to reduce neck and upper limb WMSDs at a large Canadian newspaper. Using qualitative data collection and analysis methods, we illustrate the impact of key contextual characteristics of: (1) the program (management commitment, union involvement, experience and skill of program leaders, and researcher involvement); (2) the organization (drive for productivity, management control, organizational culture); and (3) the broader social context (economic climate, nature of newspaper work, technology and nature of WMSD). We argue for increased attention to identification and response to the contextual factors affecting program implementation in order to more successfully address upstream determinants of WMSD.     

A multilayered ergonomic intervention program on reducing musculoskeletal disorders in an industrial complex: A dynamic participatory approach

Work-related musculoskeletal disorders (WMSDs) are closely identified with common complaints in different workplaces. This study aimed to implement an intervention program through which ergonomic measures were dynamically localized in industry. An interventional study, including three basic layers, namely, training workshops, participatory ergonomics (PE), and workstation redesign was fulfilled in an Iranian steel manufacturing complex from 2017 to 2020. A steering committee (SC) was formed following several meetings held for clarification of the project to the management team. The SC members then attended four organized workshops managed by an ergonomics specialist. Afterwards, the basics of ergonomics were transferred to action groups. After developing ergonomic assessment tools, the ergonomic problems were prioritized and numerous positive changes were made by the action groups. The findings of the tailored checklists revealed a load of WMSDs risk factors. All the three layers of the program were implemented as initiated. Ergonomics training workshops were then held and significant differences were observed between the participants' pre/posttest mean scores in all workshops (p < 0.001). Moreover, PE measures were exercised at all levels of the organization inducing enthusiastic motivation of the workforce to consider ergonomic requirements in the workplace. Consequently, the workers' innovative ideas and the managerial support yielded diverse workstation redesigns due to a growth in either the workers' ergonomics awareness or participatory culture grounding. A multilayered ergonomic intervention was implemented in this study. In conclusion, a multifaceted long-term follow-up intervention program could be applied to enhance workers’ health status and to raise system productivity.     

A framework for interactive work design based on motion tracking,simulation, and analysis

Because of the flexibility and adaptability of humans, manual handling work is still important in industry, especially in assembly and maintenance work. Well‐designed work operation can improve work efficiency and quality; enhance safety, and lower cost. Most traditional methods for work system analysis need physical mock‐ups and are time‐consuming. Digital mock‐up (DMU) and digital human modeling (DHM) techniques have been developed to assist ergonomic design and evaluation for a specific worker population (e.g., 95 percentile); however, the operation adaptability and adjustability for a specific individual are not considered enough. In this study, a new framework based on motion‐tracking technique and digital human simulation technique is proposed for motion–time analysis of manual operations. A motion‐tracking system is used to track a worker's operation while he/she is conducting a manual handling task. The motion data are transferred to a simulation computer for real‐time digital human simulation. The data are also used for motion type recognition and analysis either online or offline for objective work efficiency evaluation and subjective work task evaluation. Methods for automatic motion recognition and analysis are presented. Constraints and limitations of the proposed method are discussed. © 2010 Wiley Periodicals, Inc.     

Ergonomic assessment of office worker postures using 3D automated joint angle assessment

Sedentary activity and static postures are associated with work-related musculoskeletal disorders (WMSDs) and worker discomfort. Ergonomic evaluation for office workers is commonly performed by experts using tools such as the Rapid Upper Limb Assessment (RULA), but there is limited evidence suggesting sustained compliance with expert’s recommendations. Assessing postural shifts across a day and identifying poor postures would benefit from automation by means of real-time, continuous feedback. Automated postural assessment methods exist; however, they are usually based on ideal conditions that may restrict users’ postures, clothing, and hair styles, or may require unobstructed views of the participants. Using a Microsoft Kinect camera and open-source computer vision algorithms, we propose an automated ergonomic assessment algorithm to monitor office worker postures, the 3D Automated Joint Angle Assessment, 3D-AJA. The validity of the 3D-AJA was tested by comparing algorithm-calculated joint angles to the angles obtained from manual goniometry and the Kinect Software Development Kit (SDK) for 20 participants in an office space. The results of the assessment show that the 3D-AJA has mean absolute errors ranging from 5.6° ± 5.1° to 8.5° ± 8.1° for shoulder flexion, shoulder abduction, and elbow flexion relative to joint angle measurements from goniometry. Additionally, the 3D-AJA showed relatively good performance on the classification of RULA score A using a Random Forest model (micro averages F1-score = 0.759, G-mean = 0.811), even at high levels of occlusion on the subjects’ lower limbs. The results of the study provide a basis for the development of a full-body ergonomic assessment for office workers, which can support personalized behavior change and help office workers to adjust their postures, thus reducing their risks of WMSDs.     

Investigation of multiple heterogeneous relationships using a q-rung orthopair fuzzy multi-criteria decision algorithm

Neural Computing and Applications - Q-rung orthopair fuzzy (q-ROF) set is one of the powerful tools for handling the uncertain multi-criteria decision-making (MCDM) problems, various MCDM methods...     

Assessing exposure to risk factors for work-related musculoskeletal disorders using Quick Exposure Check (QEC) in taxi drivers

Work-related musculoskeletal disorders (WMSDs) are a common health problem throughout the world. This study aimed to examine the risk factors that are involved in the development of WMSDs in taxi drivers. In total 382 taxi drivers were observed using Quick Exposure Check (QEC) observational tool, which allows practitioners and workers to assess four key areas of the body. Results of the QEC scores were found to be very high for the shoulder/arm, wrist/hand and neck, whereas the scores for the back were found to be high for static use and moderate for moving. The results also showed that the occupational risk factors for WMSDs were associated with restricted postures, repetitive movements, vibration, work related stress. Essential ergonomic interventions are needed to eliminate risk of exposures to WMSDs in taxi drivers.Relevance to industryThe study results have relevance for ergonomists, health and safety practitioners as well as the drivers themselves, and helpful for estimating the main physical risk factors for WMDSs before choosing a method prior to an ergonomic intervention in industry.     

地理信息技术在环境管理中的应用

由于人们对环境的重视以及环境危机的不断加剧,人们对环境的有效管理的要求越来越高,致使新的环境管理就断出现。地理信息技术具有很强大的空间数据处理能力,因此在处理环境数据中其效用非常明显,而信息系统（GIS）是一种强有力的信息管理和分析工具,数字信息的获得及处理等过程往往离不开地理信息系统或其他相关的数字处理技术。数字信息的获取分三个阶段：数据的搜集;数据的分析（该过程包括地理信息系统与其它技术的集成）;数据的转换和信息的处理。地理信息系统作为一种信息处理工具有效地满足了以上各个阶段的需要。     

Visualization methods in analysis of detailed chemical kinetics modelling

Sensitivity analysis, principal component analysis of the sensitivity matrix, and rate-of-production analysis are useful tools in interpreting detailed chemical kinetics calculations. This paper deals with the practical use and communication of the sensitivity analysis and the related methods are discussed. Some limitations of sensitivity analysis, originating from the mathematical concept (e.g. first-order or brute force methods) or from the software-specific implementation of the method, are discussed. As supplementary tools to the current methods, three novel visual tools for analysis of detailed chemical kinetics mechanisms are introduced: (a) scaled sensitivity analysis which is especially suited for studying initiation reactions where the span of reaction rates is high; (b) automated generation of reaction pathway plots which provides an immediate graphical illustration of the chemical processes occurring; (c) explorative (or chemometric) analysis of accumulated rate of progress matrices which assist in the identification of reaction subsets. The application of these tools are demonstrated by analysing NOx enhanced oxidation of methane at 700-1200 K.