Evaluation of ergonomic approach and musculoskeletal disorders in two different organizations in a truck assembly plant

The aim of this study was to assess the ergonomic physical exposure, organizational and psychosocial factors in a truck assembly plant for two different cycle times (11 min and 8 min). A self-reported questionnaire was applied to evaluate subjective physical exposure, organizational and psychosocial factors by operators in two organization of an assembly process. The initial cycle time was 11 min (system A) and the new was 8 min (system B). The same work and assembly tasks had to be completed in both systems. However, the organization and distribution of the tasks and workstations were reorganized. The results of the questionnaire showed that subjective estimation by the operators regarding ergonomic risk factors was better in the new organization and self-reported WR-MSDs symptoms were fewer. However, exposure to risk factors and WR-MSDs symptoms was not statistically different between two cycle times. The findings provide better understanding of how organizational changes can modify ergonomic exposure in manufacturing assembly industries. Effective interventions are thus not only engineering solutions but also organizational and administrative adaptations.     

Cross-sectional study of risk factors for symptoms in the neck and shoulder area

Abstract

This study was performed in order to evaluate how individual characteristics, as well as ergonomic, organizational and psychosocial factors in the work situation are associated with early symptoms in the neck and shoulder area. Nine hundred randomly drawn subjects of the working population in a semi-rural community in Sweden were mailed a questionnaire comprising the Nordic questionnaire on musculoskeletal symptoms, questions on ergonomic, organizational and psychosocial work conditions, life style factors, and background factors. The total response rate was 73% ( n = 637). Questions on ergonomic work conditions and on organizational and psychosocial work conditions provided the measures of exposure. Prevalence ratios (PR) were calculated for symptoms in the neck and shoulder area as reported by 303 subjects. Significant determinants for early symptoms were being a female and being an immigrant, as were repetitive movements demanding precision. High work pace, low work content and work role ambiguity were significant organizational risk factors while life style characteristics did not appear as risk factors. The results suggest that symptoms are signals not only of ergonomic deficiencies in the work situation, but in particular of work organizational conditions. Special attention should be given to the work conditions of women and immigrants in preventive interventions.     

Ergonomic criteria in large-scale engineering design--II. Evaluating and applying requirements in the real world of design.

Ergonomic standards to be used in engineering design are at present being developed throughout the world. However, not much is known about how ergonomic criteria function in an organizational setting. This study investigates how engineering designers in two large-scale engineering projects evaluate ergonomic criteria that are part of the design requirements in the projects. The designers state a clear preference for specific criteria. We also show how all design criteria are subject to organizational constraints, and that specific formulations are not a guarantee for the implementation of ergonomic criteria. Emphasising a few specific criteria might have an educational impact on the designers. The active involvement of an HF specialist is also critical to ensure a positive outcome for ergonomic criteria in the design negotiation process.     

Investigation of musculoskeletal symptoms and ergonomic risk factors among female sewing machine operators in Turkey

This cross-sectional study aimed to identify the prevalence of musculoskeletal symptoms and ergonomic risks in female sewing machine operators at a textile company. The study sample comprised all female sewing machine operators in the company. The sample included 283 sewing machine operators. Data were collected through the use of the adapted Nordic Musculoskeletal Questionnaire and by direct observations via the rapid upper limb assessment (RULA) to determine ergonomic risks. RULA is a validated tool for assessment of ergonomic risks. The mean age of the women was 30.2 (SD: 8.4) and the mean number of years of employment was 13.4 (SD: 5.5). The highest prevalence rates for the women’s musculoskeletal symptoms were in the trunk (62.5%), neck (50.5%), and shoulder (50.2%). Of the women, 65% had experienced musculoskeletal pain or discomfort over the last 6 months. Pain intensity of these symptoms was assessed with a visual analogue scale. The average pain intensity of the women was found to be 3.5 (SD: 2.8). Results of the RULA scores were found to be quite high. There were no employees who received RULA scores of 1–2, which indicates acceptable postures (all scores >5). The final RULA scores of 6.9 indicate that the participants’ postures at their work stations need to be investigated immediately.

Relevance to industry

This study based on the RULA method allowed to perform a rapid and quite correct evaluation tolls for SMOs. For this research population, the research findings provided fundamental data on the prevalence of musculoskeletal symptoms and ergonomic risks among Turkish female SMOs.     

The effects of ergonomic interventions on low back moments are attenuated by changes in lifting behaviour

This study investigated the effects of ergonomic interventions involving a reduction of the mass (from 16 to 11 and 6 kg) and an increase in the initial lifting height (from pallet height to 90 cm above the ground) of building blocks in a mock-up of an industrial depalletizing task, investigating lifting behaviour as well as low back moments (calculated using a 3-D linked segment model). Nine experienced construction workers participated in the experiment, in which they removed building blocks from a pallet in the way they normally did during their work. Most of the changes in lifting behaviour that were found would attenuate the effect of the investigated interventions on low back moments. When block mass was reduced from 16 to 6 kg, subjects chose to lift the building block from a 10 (SD 10) cm greater distance from the front edge of the pallet and with a 100 (SD 66) degrees/s² higher trunk angular acceleration. When initial lifting height was increased, subjects chose to shift the building blocks less before actually lifting them, resulting in a 10.7 (SD 10) cm increase in horizontal distance of the building blocks relative to the body at the instant of peak net total moment. Despite these changes in lifting behaviour, the investigated ergonomic interventions still reduced the net total low back moment (by 4.9 (SD 2.0) Nm/kg when block mass was reduced and 53.6 (SD 41.0) Nm when initial lifting height was increased).     

Ergonomics study and analysis of workstations in Tunisian mechanical manufacturing

The workers’ performance in the mechanical manufacturing sector is the main factor for the improvement of productivity and quality. At present, it seems that the available information on the ergonomics and the working environment of the mechanical manufacturing actors is scarce. This study deals with the relationship between the working method and the workstation in injection mold manufacturing. An original methodology, based on the survey of operators using participatory ergonomic tools, is proposed in order to evaluate the ergonomic performance of 3 workstations: milling, turning, and drilling. The surveys concerned 3 operators. Obtained results showed that ergonomics play a key role in improving mechanical manufacturing. The results obtained from the analysis showed that ergonomics has a key role in the quality of the various tasks performed by operators. Using the Rapid Entire Body Assessment (RULA) and Rapid Entire Body Assessment (REBA) investigation tools, the examination of the workstations revealed 4 machining operations and 12 operator postures that have a direct influence on the performance of all machining stations. In addition, data from the analysis conducted on injection mold manufacturing revealed that neither the workstations were ergonomic nor the operators complied with the ergonomic rules. Based on the results obtained, a new standardized score is proposed for the RULA and REBA calculations. This score was applied and validated through another study conducted in a leaf spring manufacturing plant. The results of these studies were concretized by proposing the digital factory where CATIA software was used for the virtual design of the ergonomic workstations and their environments.     

Ergonomic interventions among waste collection workers: A systematic review

Waste collection workers are frequently exposed to significant occupational hazards. Even though ergonomic interventions can mitigate these occupational hazards, only a few studies have attempted to study the importance of the interventions. The current review identifies the gaps in ergonomic interventions among waste collection workers. A systematic review and a bibliometric analysis of the literature on the assessment of occupational hazards and ergonomic interventions in different countries were performed to identify the scope of the interventions. A literature search was carried out in Web of Science, PubMed and Scopus for articles published until December 2018. The search yielded seventy articles on the assessment of occupational health and ten articles on ergonomic interventions among waste collection workers. Based on the review, this paper proposes a hierarchical framework for the implementation of ergonomic interventions in waste associated occupations. The problems faced by formal and informal waste collectors are critical, particularly in developing countries and there is a growing need for low-cost interventions. It is suggested that the potential interventions have to be implemented based on the nature of occupational hazard considering social, cultural and economic factors.     

Job stress management and ergonomic intervention for work-related upper extremity symptoms

In practice the secondary prevention of work-related upper extremity (WRUE) symptoms generally targets biomechanical risk factors. Psychosocial risk factors have also been shown to play an important role in the development of WRUE symptom severity and future disability. The addition of a stress management component to biomechanically focused interventions may result in greater improvements in WRUE symptoms and functional limitations than intervening in the biomechanical risk factors alone. Seventy office workers with WRUE symptoms were randomly assigned to an ergonomics intervention group (assessment and modification of work station and stretching exercises) or a combined ergonomic and job stress intervention group (ergonomic intervention plus two 1-h workshops on the identification and management of workplace stress). Baseline, 3- and 12-month follow-up measures of observed ergonomic risks and self-reported ergonomic risks, job stress, pain, symptoms, functional limitation, and general physical and mental health were obtained from all participants. While both groups experienced significant decreases in pain, symptoms, and functional limitation from baseline to three months with improvements continuing to 12 months post baseline, no significant differences between groups were observed for any outcome measures. Findings indicate that the additional two-session job stress management component did not significantly enhance the short- or long-term improvements brought about by the ergonomic intervention alone.     

Erratum to “Behavioural change phases of different stakeholders involved in the implementation process of ergonomics measures in bricklaying”: [Applied Ergonomics 36 (2005) 449-459]

The objective of this qualitative study was to assess whether a hypothesised sequential order of behavioural change phases would be fulfilled in different groups of stakeholders involved at the start of a process to implement ergonomic measures in bricklaying teams. The measures include trestles, bricklaying scaffolds, mast climbing work platforms and cranes. The behavioural change phases were: (1) being aware of measures, (2) understanding measures, (3) wanting measures, (4) intention to buy or hire measures, (5) ability to use measures, (6) using measures (experience), and (7) continuing to use measures. Structured interviews were conducted to examine the change phases in two groups of stakeholders (employers/work planners (n=11) and foremen/bricklayers (n=9) from nine companies) thought to be relevant in the decision to adopt and use the ergonomic measures. The results show that the fulfilled behavioural change phases differ between individual stakeholders, groups of stakeholders, companies and also between ergonomic measures. The hypothesised order of fulfilled consecutive behavioural change phases for individual stakeholders has not been confirmed by this study. The relationship between fulfilled and unfulfilled change phases by each stakeholder (group) and actual use of each ergonomic measure requires further study, so as to improve the selection of suitable implementation strategies.     

Occupational stress factors in visual display terminal (VDT) operation: a review of empirical research

A review of the literature involving empirical research (experimental and field investigations) on stressful aspects of visual display terminal (VDT) operation is presented. Studies reviewed included assessment of visual fatigue and/or performance, musculoskeletal symptoms and operator attitudes towards job demands and quality of working life. In addition, some investigation included discussions and evaluations of the physical attributes of VDT workplaces; including ergonomic factors (task lighting, glare conditions, anthropometric configuration of VDT and accompanying furniture), environmental factors (temperature, humidity, radiation) and psychosocial factors (job demand, work content, work-rest schedules).

The literature reveals that levels of visual and musculoskeletal complaints among VDT operators are high. Moreover, ergonomic field assessment of VDT workplaces indicate that the majority of those examined were suboptimal with respect to existing recommendations regarding lighting, glare control and anthropometric dimensions of screen, keyboard, desk and chair. Nevertheless, evidence of causal linkages between specific ergonomic attributes of the workplace and specific patterns of symptomatology are lacking.

Finally, work demand and task structure attributes to the VDT operation were demonstrated to have strong effects on incidences of reports of visual and postural symptoms as well as on psychosocial attitudinal indicators. Hence, it is argued that approaches toward stress reduction must include job content as well as ergonomic factors.     

Ergonomic intervention research for improved musculoskeletal health: A critical review

This literature review of ergonomic intervention studies aims to identify effective ergonomic interventions for improved musculoskeletal health in the workplace and to make recommendations for quality criteria in ergonomic intervention research. To avoid ambiguity in terminology a list of definitions of the ergonomic terms used in this paper is provided in an appendix. Models were developed for use in the classification of ergonomic intervention research and to illustrate the problems in interpreting ergonomic intervention data. The relevant literature was identified by a two-step process. First the relevant literature was identified by inclusion criteria, then, quality criteria were applied to identify studies of good quality for effective intervention. These appear to be firstly “organizational culture” and secondly modifier interventions, the former using multiple interventions with high stakeholder commitment to reduce identified risk factors, and the latter especially focusing workers at risk and using measures which actively involve the individual. A list of recommendations is provided.     

Big data and smart cities: a public sector organizational learning perspective

Public sector organizations (city authorities) have begun to explore ways to exploit big data to provide smarter solutions for cities. The way organizations learn to use new forms of technology has been widely researched. However, many public sector organisations have found themselves in new territory in trying to deploy and integrate this new form of technology (big data) to another fast moving and relatively new concept (smart city). This paper is a cross-sectional scoping study—from two UK smart city initiatives—on the learning processes experienced by elite (top management) stakeholders in the advent and adoption of these two novel concepts. The findings are an experiential narrative account on learning to exploit big data to address issues by developing solutions through smart city initiatives. The findings revealed a set of moves in relation to the exploration and exploitation of big data through smart city initiatives: (a) knowledge finding; (b) knowledge reframing; (c) inter-organization collaborations and (d) ex-post evaluations. Even though this is a time-sensitive scoping study it gives an account on a current state-of-play on the use of big data in public sector organizations for creating smarter cities. This study has implications for practitioners in the smart city domain and contributes to academia by operationalizing and adapting Crossan et al’s (Acad Manag Rev 24(3): 522–537, 1999) 4I model on organizational learning.     

A systematic review of comparative studies on ergonomic assessment techniques

This review provides a systematic overview of the comparison of ergonomic assessment techniques’ output in variety of industrial sectors.The relevant publications have been classified into broad categories such as comparison of applied industry sector, trend analysis, ergonomic assessment techniques been compared, comparative studies between two ergonomic assessment techniques, frequently compared techniques, levels of Action categories used. The summary of extracted data from included papers is provided.Authors have compared the results based on observational techniques which are easy to understand and apply. Available publications related to such comparison is limited. Authors have compared and analysed the correlation between the outputs of techniques but only few researchers pointed out the exact reason of variation in outputs applied in the same task. Hence, establishing applicability of each technique required. To identify the causes of variation, the sensitivity study of exposure factor-Task-posture assessment techniques is highly required. There are few techniques which are not yet compared for checking agreement or correlation, serving as a research gap.Authors have studied and published literature review specific to one technique of ergonomic assessment. Few authors have compared the outputs from various ergonomic assessment techniques in particular sector and investigated the correlation between them. No study has been carried out till date to review available literature on comparative study of comparisons made. In this paper, two research gaps have also been identified.     

Effectiveness of ergonomic training to reduce physical demands and musculoskeletal symptoms - An overview of systematic reviews

Work-related musculoskeletal disorders are associated with awkward postures, excessive force, manual material handling and repetitive movements. This risk factors can be minimized through interventions such as ergonomic training. The literature covers several studies involving the use of this type of intervention, but there is no consensus about the effectiveness of ergonomic training. The aim of this study was to identify the available evidence about the effectiveness of ergonomic training to reduce physical work demand and musculoskeletal symptoms through an overview of systematic reviews. The searches were carried out in Pubmed/Medline, Web of Science, CINAHL, Embase and Cochrane Library. The START (State of the Art through Systematic Review, v.1.06.2) platform aided the selection and evaluation of studies. The studies were evaluated for methodological quality through the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) criteria and the implications for practice. This overview identified a large number of studies with a low to moderate level of evidence, indicating the ineffectiveness of ergonomic training alone or associated with another type of intervention in reducing physical demand and musculoskeletal symptoms in workers. The findings may have occurred due to four main factors: superficial identification of the ergonomic risk factors; lack of scientific evidence about the appropriate configurations of the types of ergonomic training; ambiguous results in the application of ergonomic training; and the difficulty in the effectiveness of the intervention. The study identified an inconsistency in the level of evidence of ergonomic training to reduce physical demand and musculoskeletal symptoms among workers.     

Negotiating participation: understanding the "how" in an ergonomic change team

In participatory ergonomic (PE) interventions, "how" effective participation by workplace parties can be achieved remains unclear. We conducted a case study of the dynamics of an ergonomic change team (ECT) process in a medium-sized (175 employees) automotive foam manufacturing plant. We present analyses of observer field notes and post-intervention interviews from which key elements on the dynamics of the "how" emerged: (1) impacts of facilitators' involvement and interests; (2) tensions in delimiting the scope of ECT activities; issues around (3) managing meetings and (4) realizing labour and management participation; and (5) workplace ECT members' difficulties in juggling other job commitments and facing production pressures. We highlight the ongoing negotiated nature of responses to these challenges by labour, management and ergonomic facilitator members of the ECT. We argue for greater examination of the social dynamics of PE processes to identify additional ways of fostering participation in ergonomic project implementation.     

Musculoskeletal symptoms due to technical preconditions in long cycle time work in an automobile assembly plant: a study of prevalence and relation to psychosocial factors and physical exposure.

The aim was to evaluate the prevailing ergonomic conditions in a parallelized flow, long cycle time, assembly system. The evaluation focused on physical exposure, psychosocial factors and work-related musculoskeletal symptoms. A random sample of 67 assembly operators was included in a cross-sectional study mainly based on questionnaires. Hand/wrist symptoms were common and related to work exposure with hand-held powered tools. In general, the self-reported physical exposure showed only a few significant associations with musculoskeletal symptoms. This may in part be explained by the ergonomic conditions generally being good, with a relatively low duration of 'combined' extreme work postures. Significant associations were found between the psychosocial work environment and musculoskeletal symptoms.     

Organizational options for preventing work-related stress in knowledge work

Recent studies point to work-related stress as an increasing problem for knowledge workers. However, the working life in knowledge-intensive companies is often described as good and stimulating. The aim of this study is to explore the organizational options for preventing work-related problems in knowledge work. This calls for a study of the characteristics of knowledge work, stress management interventions and an in-depth analysis of the organizational factors causing frustrations and work-related problems in relation to knowledge work. In a qualitative study, 27 respondents were interviewed. They represented different stakeholders in five Danish knowledge-intensive companies, which comprised two consultancies and three engineering consulting companies.The study shows that knowledge work comprises a paradox, since the same work-related or organizational issues could be experienced as both an opportunity and a source of stress. The stress interventions applied are short-term and focus on the individual; consequently, they affect long-term prevention, which focuses on changing the organizational and managerial circumstances. Finally, the in-depth analysis shows that the organizational factors in the organizational design are not aligned, which consequently has an unsolicited effect on both daily activities and the human factors.The findings suggest that if the central components in the organizational design were aligned, the benefits could include reduced absenteeism and turnover as well as higher productivity.Relevance to industryThe paper identifies organizational options on which managers, employees and ergonomists can focus when initiating new stress management practices and preventive changes aimed at redesigning knowledge work.     

Evaluation of ergonomic working conditions among standing sewing machine operators in Sri Lanka

BackgroundStanding Sewing Machine Operators (SSMOs) are engaged in highly repetitive operations, and work while standing during their entire working hours. This leads to discomforts and Musculoskeletal Disorders (MSDs). However, there is a dearth of research in SSMOs’ working conditions.Objective: Aim of the study is to evaluate the prevalence of MSDs and related ergonomic risk factors among SSMOs in the Sri Lankan textile industry.Methods: The sample included 552 female sewing machine operators. Data were collected through self-reported questionnaires which included demographic, job-related factors and Cornell Musculoskeletal Discomfort Questionnaire [CMDQ], along with the application of validated ergonomic tools (Rapid Entire Body Assessment [REBA] and Strain Index [SI]) to assess the ergonomic risks amongst them. The inter-rater reliability test ensured the reliability among observers. An individual regression model was developed for each body parts to assess the associated risk factors.Results: The highest occurrence of musculoskeletal symptoms were in knee, foot, thigh, lower leg and lower back of SSMOs. REBA grand score (4–11) indicated that workers’ postures were at medium, high and very high risk levels necessitating evaluation to change. Moreover, SI indicated medium and high risk of upper extremity disorders. Finally, regression models revealed associated risk factors with musculoskeletal symptoms among various body parts including age, Body Mass Index (BMI), marital status, SSMO experience, job satisfaction, job stress, daily walking distance to the boarding place/factory, interest in job rotation and satisfaction with the design of sewing machine.Conclusion: The findings highlighted that the prevalence of discomfort and MSDs in the lower limbs were higher than in the upper limbs among SSMOs. The findings revealed the working conditions of SSMO and emphasised the need for ergonomic interventions to minimise the MSDs among them.Relevance to industryThe findings highlighted ergonomic risks among SSMOs and associated risk factors which will help managers and researchers better understand the working conditions of SSMOs. The identified risk factors could be considered during the implementation of standing sewing operation layouts and during the selection and allocation of new employees.     

GARUSO: a gamification approach for involving stakeholders outside organizational reach in requirements engineering

Stakeholder participation is a key success factor of Requirements Engineering (RE). Typically, the techniques used for identifying and involving stakeholders in RE assume that stakeholders can be identified among the members of the organizations involved when a software system is ordered, developed or maintained—and that these stakeholders can be told or even mandated to contribute. However, these assumptions no longer hold for many of today’s software systems where significant stakeholders (in particular, end-users and people affected by a system) are outside organizational reach: They are neither known nor can they easily be identified in the involved organizations nor can they be told to participate in RE activities. We have developed the GARUSO approach to address this problem. It uses a strategy for identifying stakeholders outside organizational reach and a social media platform that applies gamification for motivating these stakeholders to participate in RE activities. In this article, we describe the GARUSO approach and report on its empirical evaluation. We found that the identification strategy attracted a crowd of stakeholders outside organizational reach to the GARUSO platform and motivated them to participate voluntarily in collaborative RE activities. From our findings, we derived a first set of design principles on how to involve stakeholders outside organizational reach in RE. Our work expands the body of knowledge on crowd RE regarding stakeholders outside organizational reach.

     

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.