Effects of job rotation on musculoskeletal complaints and related work exposures: a systematic literature review

Higher bisphenol analogues exposure levels in e-waste workers and their associations with DNA oxidative damage in Hong Kong

Bisphenol analogues (BPs) are widely used as additives in a variety of products, including the components of electronic waste (e-waste). However, limited research has been conducted to evaluate the health burden of BPs exposure from e-waste recycling, particularly among frontline workers in developed regions. This study aimed to address this gap by analyzing urinary BPs and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, from 101 e-waste workers and 100 office workers in Hong Kong collected from 06/2021 to 09/2022. E-waste workers had significantly higher overall BPs concentrations than office workers (3.476 vs. 1.816 μg/L), with notable elevations in BPA, BPP, and BPZ. Male participants (3.118 μg/L) and e-waste workers involved in dismantling or repairing e-waste (4.245 μg/L) exhibited higher BPs burdens than the females (1.849 μg/L) and workers with other job designations (1.822 μg/L), respectively. Although the estimated daily intake (EDI) for BPA was below the recommended safety threshold, e-waste workers had higher EDIs for almost all BPs than office workers. BPA was the predominant analogue in e-waste and office workers (80.74 % and 75.94 %), and correlated with other BPs in e-waste workers, indicating its pervasive use in e-waste products. Exposure to BPs, both individually and as a mixture, was significantly associated with increased 8-OHdG levels, with stronger associations among female participants and the e-waste workers. The above findings suggest that e-waste workers in Hong Kong had higher BPs exposure from e-waste recycling and carried the associated health risks, with females showing greater sensitivity to BPs.

Effectiveness of a Goldilocks work intervention to promote musculoskeletal health among industrial workers - A cluster randomized controlled trial

INTRODUCTION

Industrial workers with physically demanding work have increased risk of musculoskeletal pain. The present 12-week Goldilocks Work intervention aimed to organize work among industrial workers to comprise a 'just right' ergonomic balance of physical behaviors (i.e., sit, stand and active) intended to promote musculoskeletal health. The paper investigates the effectiveness of the intervention in reducing low back pain after work.

METHODS

83 workers across 28 workteams in a biotech organization were recruited. Workteams were randomly allocated to receive the intervention or work as usual (control). Intervention workteams implemented the Goldilocks Work planning tool to organize their work tasks towards a predefined 'just right' ergonomic balance (i.e., composition of 60% sitting, 30% standing, 10% active work and hourly task alternation). The primary outcome was low back pain intensity. Secondary outcomes were bodily pain, fatigue, physical exertion, productivity and energy after work measured in the survey, and composition and alternations of physical behaviors measured using wearable sensors.

RESULTS

The intervention was delivered almost as planned, with good quality and high adherence among most workteams. However, the intervention did not change physical behaviors towards the intended 'just right' ergonomic balance. No significant reduction in low back pain (0.07, CI 95%: -0.68; 0.82), bodily pain (0.10, CI 95%: -0.57; 0.76), tiredness (-0.53, CI 95%: -1.24; 0.19), physical exertion (-0.18, CI 95%: -0.83; 0.48), or improvement in energy (0.39, CI 95%: -1.02; 0.23) or productivity (-0.03, CI 95%: -0.77; 0.72) were found.

CONCLUSION

This Goldilocks Work intervention did not promote musculoskeletal health among industrial workers and did not change physical behaviors as intended. Thus, more research is needed into implementation strategies to change physical behaviors during productive work towards an evidence-based 'just right' ergonomic balance.

Can home care work be organized to promote health among the workers while maintaining productivity? An investigation into stakeholders' perspectives on organizational work redesign concepts based on the Goldilocks Work principles

BACKGROUND

Due to the aging population, the need for home care services is increasing in most Western countries, including Norway. However, the highly physical nature of this job could contribute to make recruiting and retaining qualified home care workers (HCWs) challenging. This issue may be overcome by adopting the Goldilocks Work principles, aiming at promoting workers' physical health by determining a "just right" balance between work demands and recovery periods while maintaining productivity. The aim of this study was to 1) gather suggestions from home care employees on suitable organizational (re)design concepts for promoting HCWs' physical health and 2) have researchers and managers define actionable behavioral aims for the HCWs for each proposed (re)design concept and evaluate them in the context of the Goldilocks Work principles.

METHODS

HCWs, safety representatives, and operation coordinators (n = 14) from three Norwegian home care units participated in digital workshops led by a researcher. They suggested, ranked, and discussed redesign concepts aimed at promoting HCWs' health. The redesign concepts were subsequently operationalized and evaluated by three researchers and three home care managers.

RESULTS

Workshop participants suggested five redesign concepts, namely "operation coordinators should distribute work lists with different occupational physical activity demands more evenly between HCWs", "operation coordinators should distribute transportation modes more evenly between HCWs", "Managers should facilitate correct use of ergonomic aids and techniques", "HCWs should use the stairs instead of the elevator", and "HCWs should participate in home-based exercise training with clients". Only the first two redesign concepts were considered to be aligned with the Goldilocks Work principles. A corresponding behavioral aim for a "just right" workload was defined: reduce inter-individual differences in occupational physical activity throughout a work week.

CONCLUSIONS

Operation coordinators could have a key role in health-promoting organizational work redesign based on the Goldilocks Work principles in home care. By reducing the inter-individual differences in occupational physical activity throughout a work week, HCWs' health may be improved, thus reducing absenteeism and increasing the sustainability of home care services. The two suggested redesign concepts should be considered areas for evaluation and adoption in practice by researchers and home care services in similar settings.

Assessing the efficacy of a job rotation for improving occupational physical and psychosocial work environment, musculoskeletal health, social equality, production quality and resilience at a commercial laundromat: protocol for a longitudinal case study

INTRODUCTION

Job rotation is a work organisation strategy used to reduce work-related exposures and musculoskeletal complaints, yet evidence for the efficacy of the approach is weak. Mismatch between job rotation and company needs, lack of full implementation, lack of exposure variation in included tasks and failure to assess variation may underlie inconclusive research findings to date. The study aims to develop a job rotation with company stakeholders, perform a process evaluation of the implementation, and determine the extent to which the intervention improves the physical and psychosocial work environment, indicators of health, gender and social equality among workers and production quality and resilience.

METHODS AND ANALYSIS

Approximately 60 production workers at a Swedish commercial laundromat will be recruited. Physical and psychosocial work environment conditions, health, productivity and gender and social equality will be assessed pre and post intervention, using surveys, accelerometers, heart rate, electromyography and focus groups. A task-based exposure matrix will be constructed, and exposure variation estimated at the level of the individual worker pre and post intervention. An implementation process evaluation will be conducted. Job rotation efficacy will be assessed in terms of improvement in work environment conditions, health, gender and social inequality, and production quality and resilience. This study will provide novel information on the effects of the job rotation on physical and psychosocial work environment conditions, production quality and rate, health and gender and social inequality among blue-collar workers in a highly multicultural workplace.

ETHICS AND DISSEMINATION

The study received approval from the Swedish Ethical Review Authority (reference number 2019-00228). The results of the project will be shared directly with the employees, managers and union representatives from the participating company, other relevant labour market stakeholders and with researchers at national and international conferences and via scientific publication.

TRIAL REGISTRATION NUMBER

The study is preregistered with the Open Science Framework (https://osf.io/zmdc8/).

Effects of Combining Occupationally Relevant Physical and Cognitive Tasks. A Systematic Review

OBJECTIVES

Physical and cognitive tasks occur together in many occupations. Previous reviews of combined tasks have mainly focused on their effects in a sports context. This review investigated to which extent combinations (concurrent or alternating) of occupationally relevant physical and cognitive tasks influence responses reflecting biomechanical exposure, stress, fatigue, performance, and well-being.

METHODS

We searched Scopus, Pubmed, Cinahl, and Psychinfo for controlled experiments investigating the effects of combinations of occupationally relevant physical and cognitive tasks in participants aged 18 to 70. In total, we identified 12 447 records. We added recent papers that had cited these studies (n = 573) to arrive at a total of 13 020 publications. After screening for relevance, 61 studies remained, of which 57 were classified to be of medium or high quality. Of the 57 studies, 51 addressed concurrent tasks, 5 alternating tasks, and 1 both concurrent and alternating tasks.

RESULTS

Most studies of concurrent physical and cognitive tasks reported negative effects, if numerically small, on indicators of biomechanical exposure, fatigue, and performance, compared to a physical task alone. Results were mixed for stress indicators, and well-being was too little studied to justify any conclusions. Effects depended on the tasks, including their intensity and complexity. Alternating physical and cognitive tasks did not appear to influence outcomes much, compared to having passive breaks in-between physical tasks.

CONCLUSIONS

The reviewed evidence indicated that concurrent physical and cognitive work tasks have negative, yet small effects on biomechanical indicators, fatigue and performance, compared to performing the physical task alone, but only if the physical task is intense, and the cognitive task is complex. Alternating between physical and cognitive tasks may have similar effects as breaking up physical tasks by passive breaks, but studies were few. Future studies should address ecologically valid combinations of physical and cognitive tasks, in particular in controlled field studies devoted to the long-term effects of combined work.

Using a Back Exoskeleton During Industrial and Functional Tasks-Effects on Muscle Activity, Posture, Performance, Usability, and Wearer Discomfort in a Laboratory Trial

OBJECTIVE

To investigate the effect of using a passive back-support exoskeleton (Laevo V2.56) on muscle activity, posture, heart rate, performance, usability, and wearer comfort during a course of three industrial tasks (COU; exoskeleton worn, turned-on), stair climbing test (SCT; exoskeleton worn, turned-off), timed-up-and-go test (TUG; exoskeleton worn, turned-off) compared to no exoskeleton.

BACKGROUND

Back-support exoskeletons have the potential to reduce work-related physical demands.

METHODS

Thirty-six men participated. Activity of erector spinae (ES), biceps femoris (BF), rectus abdominis (RA), vastus lateralis (VL), gastrocnemius medialis (GM), trapezius descendens (TD) was recorded by electromyography; posture by trunk, hip, knee flexion angles; heart rate by electrocardiography; performance by time-to-task accomplishment (s) and perceived task difficulty (100-mm visual analogue scale; VAS); usability by the System Usability Scale (SUS) and all items belonging to domains skepticism and user-friendliness of the Technology Usage Inventory; wearer comfort by the 100-mm VAS.

RESULTS

During parts of COU, using the exoskeleton decreased ES and BF activity and trunk flexion, and increased RA, GM, and TD activity, knee and hip flexion. Wearing the exoskeleton increased time-to-task accomplishment of SCT, TUG, and COU and perceived difficulty of SCT and TUG. Average SUS was 75.4, skepticism 11.5/28.0, user-friendliness 18.0/21.0, wearer comfort 31.1 mm.

CONCLUSION

Using the exoskeleton modified muscle activity and posture depending on the task applied, slightly impaired performance, and was evaluated mildly uncomfortable.

APPLICATION

These outcomes require investigating the effects of this passive back-supporting exoskeleton in longitudinal studies with longer operating times, providing better insights for guiding their application in real work settings.

Development of Modular and Adaptive Laboratory Set-Up for Neuroergonomic and Human-Robot Interaction Research

The industry increasingly insists on academic cooperation to solve the identified problems such as workers' performance, wellbeing, job satisfaction, and injuries. It causes an unsafe and unpleasant working environment that directly impacts the quality of the product, workers' productivity, and effectiveness. This study aimed to give a specialized solution for tests and explore possible solutions to the given problem in neuroergonomics and human–robot interaction. The designed modular and adaptive laboratory model of the industrial assembly workstation represents the laboratory infrastructure for conducting advanced research in the field of ergonomics, neuroergonomics, and human–robot interaction. It meets the operator's anatomical, anthropometric, physiological, and biomechanical characteristics. Comparing standard, ergonomic, guided, and collaborative work will be possible based on workstation construction and integrated elements. These possibilities allow the industry to try, analyze, and get answers for an identified problem, the condition, habits, and behavior of operators in the workplace. The set-up includes a workstation with an industry work chair, a Poka–Yoke system, adequate lighting, an audio 5.0 system, containers with parts and tools, EEG devices (a cap and smartfones), an EMG device, touchscreen PC screen, and collaborative robot. The first phase of the neuroergonomic study was performed according to the most common industry tasks defined as manual, monotonous, and repetitive activities. Participants have a task to assemble the developed prototype model of an industrial product using prepared parts and elements, and instructed by the installed touchscreen PC. In the beginning, the participant gets all the necessary information about the experiment and gets 15 min of practice. After the introductory part, the EEG device is mounted and prepared for recording. The experiment starts with relaxing music for 5 min. The whole experiment lasts two sessions per 60 min each, with a 15 min break between the sessions. Based on the first experiments, it is possible to develop, construct, and conduct complex experiments for industrial purposes to improve the physical, cognitive, and organizational aspects and increase workers' productivity, efficiency, and effectiveness. It has highlighted the possibility of applying modular and adaptive ergonomic research laboratory experimental set-up to transform standard workplaces into the workplaces of the future.

Designing industrial work to be 'just right' to promote health - a study protocol for a goldilocks work intervention

BACKGROUND

The Goldilocks Work Principle expresses that productive work should be designed to promote workers' health. We recently showed that it is feasible to develop and implement modifications to productive work that change physical behaviors (i.e. sitting, standing and being active) in a direction that may promote health among industrial workers. Therefore, the aim of the present study is to conduct a cluster randomised controlled trial investigating health effects of implementing the Goldilocks Work intervention among industrial workers.

METHODS

Our implementation plan consists of educating work teams, organizing implementation meetings, and providing feedback to workers. Three meetings with a preselected local workplace group will be scheduled. The first meeting educates the group to use a planning tool by which work can be planned to have 'just right' physical behaviors. The second and third meetings will focus on supporting implementation of the tool in daily work. An expected 28 clusters of work teams across two participating production sites will be randomized to either intervention or control group. Data collection will consist of 1) questionnaires regarding work and musculoskeletal health, 2) wearable sensor measurements of the physical behavior, and 3) assessment of general health indicators, including BMI, blood pressure, and fat percentage. The primary outcome is musculoskeletal health, measured by low back pain intensity, and secondary outcomes are 1) physical behaviors at work, 2) accumulated time in long bouts of sitting, standing, and being active and 3) perceived fatigue and energy during work. Furthermore, implementation and cost of the intervention will be evaluated based on questionnaires and data from the planning tool completed by the workers.

DISCUSSION

This study will evaluate the effectiveness and implementation of a 12 - weeks Goldilocks Work intervention with the aim of improving musculoskeletal health among industrial workers. The cluster randomized controlled study design and the evaluation of the implementation, results and costs of the intervention will make it capable of contributing with valuable evidence of how productive work may be designed to promote industrial workers' health.

TRIAL REGISTRATION

Clinical trial registration was assigned 10-09-2021 (ISRCTN80969503). https://doi.org/10.1186/ISRCTN80969503.

An exploratory study comparing three work/rest schedules during simulated repetitive precision work

The pattern of work and rest can influence both physical fatigue and task performance in manual operations. However, there is relatively limited evidence regarding the influences of specific work/rest schedules in tasks requiring high repetitiveness and precision demands, along with relatively low exertion levels. Eighteen participants completed an exploratory study that simulated such tasks, to compare the effects of three distinct work/rest schedules (i.e. short frequent [short] and long infrequent breaks [long], and a self-selected schedule) on muscle fatigue, task performance (in terms of accuracy and speed), and preference. Schedules with long or self-selected breaks generally induced less muscle fatigue, compared with the short break condition. Participants preferred the self-selected condition the most and the long-break condition the least. The different schedules tested did not influence task performance. A self-selected schedule may be beneficial for repetitive precision task, to achieve a balance across muscle fatigue, task performance, and individual preference. Practitioner summary: Influences of three work/rest schedules (i.e. short and long breaks, and a self-selected schedule) on fatigue, performance, and preference were explored during repetitive precision tasks. Schedules with long or self-selected breaks induced less muscle fatigue and none of the three schedules influenced performance. A self-selected schedule was the most preferred.

Relationship between job rotation and work-related low back pain: a cross-sectional study using data from the fifth Korean working conditions survey

Background

Job rotation was introduced in various industries as a strategic form of work for improving workers' job skills and health management. This study aims to examine the relationship between job rotation and work-related low back pain (LBP), one of the typical work-related musculoskeletal symptoms of Korean workers.

Methods

We conducted this study using the data of the 5th Korean Working Conditions Survey (KWCS). As the subject of this study, 27,163 wage workers were selected, and classified into three groups according to occupational type (white-collar, service and sales, and blue-collar). In this study, job rotation means to change the work-related activities with other colleagues periodically and work-related LBP was defined as whether there was work-related LBP in the last 12 months. Chi-square test and logistic regression were used to analyze the relationship between job rotation and work-related LBP.

Results

Out of 27,163 workers, 2,421 (8.9%) answered that they had job rotation and 2,281 (8.4%) answered that they experienced work-related LBP. According to the results from logistic regression, job rotation was significantly associated with low prevalence of work-related LBP among blue-collar workers (odds ratio [OR]: 0.71, 95% confidence interval [CI]: 0.58–0.88), whereas no significant relationship was observed among white-collar, service and sales groups. In addition, the negative association between job rotation and work-related LBP among blue-collar workers was more pronounced when exposed to ergonomic risk factors (uncomfortable posture OR: 0.79, 95% CI: 0.64–0.98; heavy work OR: 0.74, 95% CI: 0.57–0.96; repetitive work OR: 0.74, 95% CI: 0.60–0.92).

Conclusions

Job rotation was associated with low prevalence of work-related LBP among workers in the blue-collar occupational group in Korea. It is necessary to evaluate the effect of job rotation by occupational type and introduce an appropriate method of job rotation to reduce workers' work-related musculoskeletal symptoms.

Fatigue, Stress, and Performance during Alternating Physical and Cognitive Tasks-Effects of the Temporal Pattern of Alternations

In occupational life, performing cognitive work tasks in between fatiguing physical work tasks may allow recovery and reduce stress without losing productive working time. The temporal pattern of such alternations is likely a determinant of the recovery effect, influencing both stress and fatigue; the difficulty of the cognitive task (CT) would also be a likely determinant. The aim of this study was to determine to what extent the temporal pattern of alternations between a repetitive physical task and a CT of different difficulties influenced perceived fatigability, performance fatigability, stress-related outcomes, and performance. Fifteen women performed four work sessions comprising 110 min of repeated bouts of a repetitive physical task (pipetting), alternating with a CT (n-back). Sessions differed in bout cycle time (short: 7 + 3 min versus long: 14 + 6 min) and CT difficulty (CTdiff; easy versus difficult). Fatigue was assessed from recordings of maximal voluntary contraction force in shoulder elevations and handgrip pre- and post-work, electromyography (EMG) from the right trapezius and right forearm extensors during work, and repeated self-ratings of fatigue and pain throughout the session. Stress was assessed using electrocardiography (heart rate variability), salivary alpha-amylase, and self-reports. Perceived fatigue increased significantly over time for all protocols and more in long-cycle than short-cycle conditions. EMG activity did not increase markedly over time in any condition. Neither objective nor subjective indicators suggested that stress increased over time, regardless of the temporal pattern. Pipetting performance remained stable in all conditions. Cognitive performance, measured by the proportions of correct positive and false positive answers, differed between CTdiff levels but remained stable over time, with no significant difference between temporal patterns. In summary, temporal patterns of alternating tasks influenced fatigue to some extent but had no obvious influence on stress indicators or performance. Thus, designing job rotation with alternating physical and cognitive work should consider the temporal patterns of alternations to minimize fatigue.

Challenges arising for older workers from participating in a workplace intervention addressing work ability: a qualitative study from Germany

OBJECTIVE

Studies examining what renders workplace interventions to sustain and promote work ability of older workers successful have largely neglected older workers´ perspective. This paper outlines the results of a study with regard to older workers´ experiences and expectations of a workplace intervention. Based on these findings, some reflections on how to improve the design and the implementation of workplace interventions for older workers are provided.

METHODS

Semi-structured interviews were conducted with older workers (N = 8) participating in a workplace intervention undertaken at one production site of a large manufacturing company in Baden-Wurttemberg/Germany. The interview guide included questions on participants´ experiences with and expectations of the intervention. The interviews were recorded, transcribed verbatim and analyzed using qualitative content analysis according to Mayring (2014).

RESULTS

Older workers´ reported some challenges they face due to their participation in the workplace intervention. These resulted from the work environment (physical challenges), the work process design (new long work cycle), the work organization (tight time allowances, little job rotation, change of teams, age stereotypes) and the management of the workplace intervention (bad information, feeling of occupational insecurity and lack of being valued).

CONCLUSIONS

The study shows that challenges arising for older workers from their participation in the workplace intervention may have counteracted the promotion of work ability. As findings suggest, some of these challenges might have been avoided either by considering workers´ perspective during design and implementation of an intervention or by referring to evidence on aging and work ability.

Sustainable Working Life in a Swedish Twin Cohort-A Definition Paper with Sample Overview

Background: A unified or consensus definition of “sustainable working life” remains lacking, although studies investigating risk factors for labour market exit are numerous. In this study, we aimed (1) to update the information and to explore a definition of “sustainable working life” via a systematic literature review and (2) to describe the working life trajectories via the prevalence of sickness absence (SA), disability pension (DP), and unemployment in a Swedish twin cohort to provide a sample overview in our Sustainable Working Life-project. Methods: A systematic literature review was conducted to explore the studies with the search phrase “sustainable working life” in PubMed, PsycInfo, and the Web of Science Database of Social Sciences in January 2021, resulting in a total of 51 references. A qualitative synthesis was performed for the definitions and the measures of “sustainable working life.” Based on the Swedish Twin project Of Disability pension and Sickness absence (STODS), the current dataset to address sustainable working life includes 108 280 twin individuals born between 1925 and 1990. Comprehensive register data until 2016 for unemployment, SA and DP were linked to all individuals. Using STODS, we analysed the annual prevalence of SA, DP, and unemployment as working life trajectories over time across education and age groups. Results: The reviewed 16 full articles described several distinct definitions for sustainable working life between 2007 and 2020 from various perspectives, i.e., considering workplaces or employees, the individual, organizational or enterprise level, and the society level. The definition of “sustainable working life” appearing most often was the swAge-model including a broad range of factors, e.g., health, physical/mental/psychosocial work environment, work motivation/satisfaction, and the family situation and leisure activities. Our dataset comprised of 81%–94% of individuals who did not meet SA, DP, or unemployment during the follow-up in 1994–2016, being indicative for “sustainable working life.” The annual prevalence across years had a decreasing trend of unemployment over time, whereas the prevalence of SA had more variation, with DP being rather stable. Both unemployment and DP had the highest prevalence among those with a lower level of education, whereas in SA, the differences in prevalence between education levels were minor. Unemployment was highest across the years in the youngest age group (18–27 years), the age group differences for SA were minor, and for DP, the oldest age group (58–65 years) had the highest prevalence. Conclusions: No consensus exists for a “sustainable working life,” hence meriting further studies, and we intend to contribute by utilising the STODS database for the Sustainable Working Life project. In the upcoming studies, the existing knowledge of available definitions and frameworks will be utilised. The dataset containing both register data and self-reports enables detailed follow-up for labour market participation for sustainable working life.

Comparing upper arm and trunk kinematics between manufacturing workers performing predominantly cyclic and non-cyclic work tasks

Musculoskeletal disorders (MSDs) are common among manufacturing workers. Exposure to non-neutral postures and high movement speeds associated with MSDs among manufacturing workers may depend on the extent of the variability in the work tasks performed (i.e., predominantly "cyclic" versus "non-cyclic" work). The objectives of this study were to (i) compare mean levels of full-shift exposure summary metrics based on both posture and movement speed between manufacturing workers performing predominantly cyclic (n = 18) and non-cyclic (n = 17) tasks, and (ii) explore patterns of between- and within-worker exposure variance and between-minute (within-shift) exposure level and variation within each group. Inertial sensors were used to measure exposures for up to 15 full shifts per participant. Results indicated (i) substantially higher upper arm and trunk movement speeds among workers performing predominantly cyclic tasks relative to workers performing non-cyclic tasks despite similar postures, and (ii) greater exposure variability both between and within workers in the non-cyclic group.

Development and Implementation of 'Just Right' Physical Behavior in Industrial Work Based on the Goldilocks Work Principle-A Feasibility Study

The Goldilocks Work Principle expresses that productive work should be redesigned to comprise physical behaviors of different intensities in a composition promoting workers' health and fitness. This study is the first to assess the feasibility of redesigning work in an industrial setting according to the Goldilocks Work Principle. We recruited workers (n = 20) from a brewery in Denmark, and we conducted a participatory 16-week intervention including a workshop and two consultations. The workshop aimed to support the workers in modifying their work, while the consultations assisted the eventual implementation. Feasibility was evaluated as per three aspects: (1) developing modifications of work, (2) implementing these modifications, and (3) changing physical behavior and self-reported fatigue, pain and energy. The three aspects were addressed through records completed by the workers, measurements of workers' physical behavior and intensity during 'control' workdays (i.e., usual work) and 'intervention' workdays (i.e., modified work), and self-reported fatigue, pain and energy level following both types of workday. Five modifications to work were developed, and three of these five modifications were implemented. To some extent, physical behavior and intensity changed as intended during 'intervention' workdays compared to 'control' workdays. Workers were also less fatigued, had less pain, and had more energy after 'intervention' workdays. These results suggest that it is feasible to develop and implement modified work based on the Goldilocks Work Principle among industrial workers. However, we also identified several barriers to the implementation of such modifications.

More Hype Than Substance? A Meta-Analysis on Job and Task Rotation

Although there exist numerous publications on job and task rotation from various disciplines, there is no consistent evidence of their effectiveness. Drawing on theories from industrial and organizational psychology, knowledge management, ergonomics, and management science, we meta-analytically investigated relationships between job/task rotation and employee attitudes, learning and development, psychological and physical health, and organizational performance. Due to a conceptual overlap and frequent confusion of terminology, we analyzed the design of the rotation (job rotation vs. task rotation) as a possible moderator. The three-level meta-analysis on 56 studies (N = 284,086) showed that rotation was significantly associated with job satisfaction (r = 0.27), organizational commitment (r = 0.16), career success (r = 0.31), labor flexibility (r = 0.32), general psychological health (r = 0.20), stress/burnout (r = -0.13), individual performance (r = 0.13), and productivity (r = 0.13). Positive relationships between rotation and physical health could only be found when rotation was compared to high-intensity work. Task rotation yielded stronger relationships with attitudinal outcomes, job rotation with learning and development, psychological health, and organizational performance outcomes. Further moderator analyses showed that individualism decreased relationships between task rotation and attitudes, and correlations with organizational performance and physical health were stronger for subjective measures. The findings indicate that many expectations toward job and task rotation are not fully supported.

Stress-Related Responses to Alternations between Repetitive Physical Work and Cognitive Tasks of Different Difficulties

Alternating between physical and cognitive tasks has been proposed as an alternative in job rotation, allowing workers to recover from the physical work while still being productive. However, effects of such alternations on stress have not been investigated. This controlled experiment aimed at determining the extent to which stress-related responses develop during alternating physical and cognitive work, and to determine the extent to which cognitive task (CT) difficulty influences these responses. Fifteen women performed three sessions of 10 consecutive work bouts each including a seven-minute repetitive physical task (pipetting) and a three-minute CT (n-back) at one of three difficulty levels. Stress was assessed in terms of changes in heart rate variability, blood pressure, salivary alpha-amylase, salivary cortisol, perceived stress, and cognitive performance. The work session did not result in any marked stress response, and CT difficulty did not significantly influence stress, apart from alpha-amylase being higher at the easiest CT (F = 5.34, p = 0.02). Thus, according to our results, alternating between repetitive physical tasks and cognitive tasks may be a feasible alternative to classic job rotation between physical tasks only, even if the cognitive task is quite difficult. Future studies should address possible effects of the temporal pattern of alternations, and combine even other occupationally relevant tasks, preferably for extended periods of time.

Job rotation and work-related musculoskeletal disorders: a fatigue-failure perspective

Job rotation is an organisational strategy that can be used, in part, to reduce occupational exposure to physical risk factors associated with work-related musculoskeletal disorders (MSDs). Recent studies, however, suggest that job rotation schedules may increase the overall risk of injury to workers included in the rotation scheme. We describe a novel optimisation framework evaluating the effectiveness of a job rotation scheme using the fatigue failure model of MSD development and a case study with real injury data. Results suggest that the effect of job rotation is highly-dependent on the composition of the job pool, and inclusion of jobs with higher risk results in a drastic decrease in the effectiveness of rotation for reducing overall worker risk. The study highlights that in cases when high-risk jobs are present, job redesign of those high risk tasks should be the primary focus of intervention efforts rather than job rotation. Practitioner summary: Job rotation is often used in industry as a method to 'balance' physical demands experienced by workers to reduce musculoskeletal disorder (MSD) risk. This article examines the efficacy of reducing MSDs through job rotation using numerical simulation of job rotation strategies and utilising the fatigue failure model of MSD development.

Evidence of Workplace Interventions-A Systematic Review of Systematic Reviews

Work environment factors are highly correlated with employees' health and well-being. Our aim was to sum up current evidence of health promotion interventions in the workplace, focusing on interventions for the prevention of musculoskeletal disorders, psychological and behavioral disorders as well as interventions for older employees and economic evaluations. We conducted a comprehensive literature search including systematic reviews published from April 2012 to October 2017 in electronic databases and search engines, websites of relevant organizations and institutions. It consisted of simple and specific terms and word combinations related to workplace health promotion based on the search strategy of a previous review. After full-text screening, 74 references met the eligibility criteria. Using the same search strategy, there was a higher proportion of relevant high-quality studies as compared with the earlier review. The heterogeneity of health promotion interventions regarding intervention components, settings and study populations still limits the comparability of studies. Future studies should also address the societal and insurer perspective, including costs to the worker such as lost income and lost time at work of family members due to caregiving activities. To this end, more high-quality evidence is needed.

Alternations between physical and cognitive tasks in repetitive work - effect of cognitive task difficulty on fatigue development in women

In a context of job rotation, this study determined the extent to which the difficulty of a cognitive task (CT) interspersed between bouts of repetitive, low-intensity work (pipetting) influences recovery from fatigue. Fifteen participants performed three experimental sessions, each comprising 10 repeats of a 7 min + 3 min combination of pipetting and CT. The CT was easy, moderate or hard. Surface electromyography (EMG amplitude of the forearm extensor and trapezius muscles) and self-reports was used to assess fatigability. Perceived fatigue and trapezius EMG amplitude increased during sessions. CT difficulty influenced fatigue development only little, besides forearm extensor EMG increasing more in CT3 than in CT1 and CT2. During CT bouts, fatigability recovered, and to a similar extent irrespective of CT. Thus, CT difficulty influenced recovery of perceived as well as performance fatigability to a minor extent, and may not be a critical issue in job rotation comprising alternating physical and cognitive tasks. Practitioner summary: Alternations between physical and cognitive tasks may be an attractive option for job rotation. In this study on women, we show that the difficulty of the cognitive task influences recovery from fatigue only little and we conclude that cognitive difficulty, within reasonable limits, may be a minor issue in job rotation.

Analysis of Required Investigations of Work-Related Musculoskeletal Disorders in Spain

Musculoskeletal disorders (MSD) are the most common source of occupational health problems in Western countries. In Spain, musculoskeletal disorders (MSDs) can be reported either as accidents or occupational diseases. When reported as an occupational disease, a full diagnosis is performed, as the compensation system needs the approval of the social security authority and a mandatory investigation has to be performed. Although many methods are available for investigating the causes of occupational accidents, occupational diseases have not been analysed with the same depth, and there is a lack of investigation methods. This paper aims to analyse the role of 43 occupational investigations of causes of musculoskeletal diseases in the prevention cycle. This study is based on the occupational investigations performed by workplaces' occupational health and safety specialists when musculoskeletal diseases are reported. The analysis of the data involves descriptive statistics and the Φ coefficient. Based on administrative data, 68 workplaces employing 15,260 workers were surveyed and 41 workplaces with 13,201 workers submitted valid questionnaires to be analysed. The most frequent cause of reported musculoskeletal disease, in terms of primary risk, is repetitive movement. The only proposed measure with a significant association to the exposure by repetitive movements is job rotation (alternating workers between tasks within a job or between activities as a means to vary different levels of exposure). The investigation of occupational diseases has been useful in most of the cases for proposing preventive measures. Most of the workplaces surveyed have performed investigations and adopted preventive measures, but the managers of some workplaces were not aware of any disease notification regarding their workers when surveyed. More research is needed to provide tools for this important task.

Radio frequency identification to measure the duration of machine-paced assembly tasks: Agreement with self-reported task duration and application in variance components analyses of upper arm postures and movements recorded over multiple days

Technical advances in inertial measurement units (IMUs) with data logging functionality have enabled multi-day collection of fullshift upper arm postures and movements. Such data are useful for characterizing job-level exposures and, when coupled with task-level information, can inform interventions to mitigate high-exposure tasks. Previously reported methods for capturing task-level information, however, were limited primarily to self-report diaries or direct observation. In this study of machine-paced manufacturing workers (n=6), a low-cost radio frequency identification (RFID) system was used to collect information about when, and for how long, specific assembly tasks were performed during up to 14 consecutive work shifts (76 total work shifts across the six participants). The RFID data were compared to information collected with a self-report diary using Bland-Altman analyses. In addition, the RFID data were paired with IMU data to identify task-level exposures from within full-shift recordings of upper arm postures and movements. These data were then used to estimate the relative contributions of between- and within-worker sources of variance to overall variance in posture and movement summary measures using hierarchical random-effects analysis of variance (ANOVA) techniques. Average estimates of daily task duration based on RFID data were comparable to estimates obtained by self-report (mean bias < ±1 minute) but with substantial variability (limits of agreement > ±100 minutes). In addition, the ANOVA models containing task-level information suggested a substantial amount of the overall exposure variance was attributed to repeated observations of the same task within a work day. These findings (i) suggest that while the RFID system used in this study performed adequately, further refinement, validation, and/or alternative strategies may be needed and (ii) underscore the importance of repeated full-shift and task-based measurement approaches in characterizing physical exposures, even in machine-paced environments.

Variation in upper extremity, neck and trunk postures when performing computer work at a sit-stand station

Sit-stand tables are introduced in offices to increase variation in gross body posture, but the extent to which upper body posture variation is also affected has not previously been addressed. Neck, trunk, and upper arm postures (means and minute-to-minute variances) were determined during periods of sitting and standing from 24 office workers using sit-stand tables to perform computer work. Posture variability resulting from different temporal compositions of sitting and standing computer work was then predicted for the neck, trunk and upper arm by simulations. Postural variability during computer work could be increased up to three-fold when 20-60% of the work was performed standing (i.e. 40-80% performed sitting), compared to performing computer work only sitting. The exact composition of sit-stand proportions leading to maximum variability, as well as the potential size of the increase in variability, differed considerably between workers. Guidelines for sit-stand table use should note these large inter-individual differences.

Anthropometric data for wheelchair users: a systematic literature review

The wheelchair user population has special requirements that should be met. However, existing anthropometric data for this specific population are limited. This article characterizes and compares the available literature on anthropometric data of wheelchair users to allow for better understandings and use of data in future studies. A systematic literature review was conducted, where inclusion and exclusion criteria were defined. Forty-one articles were selected to be included in this review. The results show that there is limited information available on wheelchair users' anthropometrics. There is a lack of consistency between studies, regarding the measurements collected, samples used and methods applied. These methodological issues and differences between studies make it difficult to ensure good comparisons of databases and populations and proper designs of spaces and equipment. This study provides valuable information for future studies that need to use anthropometric data, for research and development of new products targeting wheelchair users.

An Upper Extremity Risk Assessment Tool Based on Material Fatigue Failure Theory: The Distal Upper Extremity Tool (DUET)

OBJECTIVE

Musculoskeletal tissues repeatedly loaded in vitro fail in accordance with material fatigue failure theory, and there is evidence to suggest that the same process occurs in vivo. The current paper presents a new upper extremity risk assessment tool, the Distal Upper Extremity Tool (DUET), predicated on material fatigue failure theory.

METHODS

DUET requires an estimate of force exertion level and the number of repetitions performed to derive estimates of damage and probabilities of experiencing a distal upper extremity outcome. Damage accrued over multiple tasks may be summed to estimate the cumulative damage (CD) accrued over a workday. Validation of this tool was performed using five distal upper extremity (DUE) outcomes (involving medical visits and pain) from an existing epidemiological database involving data from six automotive manufacturing plants. Logistic regression was used to assess the association of the log of the DUET CD measure to DUE outcomes.

RESULTS

Results demonstrated that the log of the DUET CD measure was highly associated with all five DUE outcomes in both crude analyses and those adjusted for site, age, gender, and body mass index ( p < .01). A model relating the continuous DUET log CD score to the probability of the DUE outcome Injury + Pain Last Year was developed, which demonstrated a significant dose-response relationship.

CONCLUSIONS

Results suggest that fatigue failure-based risk assessment techniques are highly associated with DUE outcomes and provide support for the notion that an underlying fatigue failure process may be involved in the development of upper extremity musculoskeletal disorders.

Task rotation in an underground coal mine: A pilot study

BACKGROUND

Task rotation is used to decrease the risk of workplace injuries and improve work satisfaction.

OBJECTIVE

To investigate the feasibility, benefits and challenges of implementing a task rotation schedule within an underground coalmine in NSW, Australia.

METHODS

A mixed method case control pilot study with the development and implementation of a task rotation schedule for 6 months with two work crews. A questionnaire including The Nordic Musculoskeletal Questionnaire, The Need for Recovery after Work Scale, and The Australian WHOQOL- BREF Australian Edition was used to survey workers at baseline, 3 and 6 months. A focus group was completed with the intervention crew and management at the completion of the study.

RESULTS

In total, twenty-seven participants completed the survey. Significant improvements in the psychological and environmental domains of the WHOQOL-BREF questionnaire were found in the intervention crew. Musculoskeletal pain was highest in the elbow, lower back and knee, and fatigue scores improved, across both groups. The intervention crew felt 'mentally fresher', 'didn't do the same task twice in a row', and 'had more task variety which made the shift go quickly'.

CONCLUSION

Task rotation was positively regarded, with psychological benefits identified. Three rotations during a 9-hour shift were feasible and practical in this environment.

Within and between Individual Variability of Exposure to Work-Related Musculoskeletal Disorder Risk Factors

Industrial companies indicate a tendency to eliminate variations in operator strategies, particularly following implementation of the lean principle. Companies believe when the operators perform the same prescribed tasks, they have to execute them in the same manner (completing the same gestures and being exposed to the same risk factors). They attempt to achieve better product quality by standardizing and reducing operational leeway. However, operators adjust and modify ways of performing tasks to balance between their abilities and the requirements of the job. This study aims to investigate the variability of exposure to physical risk factors within and between operators when executing the same prescribed tasks. The Ergonomic Standard method was used to evaluate two workstations. Seven operators were observed thirty times between repeated cycle times at those workstations. The results revealed the variability of exposure to risk factors between and within operators in the repeated execution of the same tasks. Individual characteristics and operators’ strategies might generate the variability of exposure to risk factors that may be an opportunity to reduce the risks of work-related musculoskeletal disorders (WR-MSDs). However, sometimes operators’ strategies may cause overexposure to risk factors; operators most often adopt such strategies to undertake their tasks while reducing the workload.

An investigation into four different sit-stand workstation use schedules

Twelve office workers participated in a study investigating effects of four sit/stand schedules (90-min sit/30-min stand, 80/40, 105/15, and 60/60) via several objective and subjective measures (muscle fatigue, foot swelling, spinal shrinkage, and self-reported discomfort). Results showed that there were no significant differences in shoulder and low back static muscle activities between sitting and standing. Muscle fatigue was developed during workday under all schedules. The longest standing schedule seemed to have a tendency of reducing muscle fatigue. None of the schedules helped or worsened foot swelling and spinal shrinkage. More active break-time activities seemed reducing muscle fatigue and foot swelling. While the self-reported bodily discomfort levels were generally low, the preferred schedules among the participants were varied, although the least standing schedule was the least preferred. We may conclude that effects of using sit-stand workstation to improve musculoskeletal health may be limited but promoting more active break-time activities can help. Practitioner Summary: Sit-stand workstations are used to reduce work-related musculoskeletal disorders. This study shows that office workers prefer sit/stand durations in the range between 1:1 and 3:1. Longer standing may have the potential to reduce muscle fatigue. However, active break-time activities may be more effective in reducing muscle fatigue and foot swelling.

Variation at work: alternations between physically and mentally demanding tasks in blue-collar occupations

The aims of this questionnaire study were to describe the occurrence and desired number of alternations between mental and physical tasks in industrial and non-industrial blue-collar work, and determine to which extent selected personal and occupational factors influence these conditions. On average, the 122 participating workers (55 females) reported to have close to four alternations per day between mental and physical tasks, and to desire more alternations than they actually had. They also expressed a general preference for performing a physical task after a mental task and vice versa. In univariate regression models, the desired change in task alternations was significantly associated with gender, age, occupation, years with current work tasks and perceived job control, while occupation was the only significant determinant in a multiple regression model including all factors. Our results suggest that alternations between productive physical and mental tasks could be a viable option in future job rotation. Practitioner Summary: We addressed attitudes among blue-collar workers to alternations between physically and mentally demanding tasks. More alternations were desired than those occurring in the job, and workers preferred performing a physical task after a mental and vice versa. Alternating physical and mental tasks could, thus, be a viable option in job rotation.

Full-shift and task-specific upper extremity muscle activity among US large-herd dairy parlour workers

US large-herd dairy parlour workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study was to estimate and compare full-shift and task-specific muscle activity of the upper extremity among parlour workers. Surface electromyography data were recorded continuously throughout a full work shift for each participant (n = 60). For a subset of participants (n = 33), muscular effort was estimated for milking task cycles. Lower muscle activity levels and higher per cent muscular rest was observed among rotary parlour participants as compared to herringbone and parallel parlour participants for anterior deltoid, forearm flexor and forearm extensor muscles. These findings suggest rotary parlours may offer workstation designs or work organisational dynamics which may be more beneficial to the health and performance of the worker, as compared to parallel or herringbone parlours. Practitioner Summary: Study findings suggest milking parlour configurations present different biomechanical demands on workers which may influence worker health and performance. Our findings will enable more informed decisions regarding both engineering (e.g. parlour configuration or milking equipment) and administrative (e.g. work organisation) control strategies for large-herd milking parlours.

Effectiveness of job rotation for preventing work-related musculoskeletal diseases: a cluster randomised controlled trial

OBJECTIVE

Job rotation is an organisational strategy widely used on assembly lines in manufacturing industries to mitigate workers' exposure so as to prevent musculoskeletal disorders. This study aimed to evaluate the effectiveness of job rotation for reducing working hours lost due to sick leave resulting from musculoskeletal diseases.

METHODS

The design consisted of a 1-year cluster randomised controlled trial with a blinded assessor. Production sectors of the textile industry were randomised to intervention and control groups. Both groups received ergonomic training. The intervention group performed a job rotation programme. The primary outcome measure was number of working hours lost due to sick leave as a result of musculoskeletal disease (ICD-10). The secondary outcome measures were musculoskeletal symptoms (Yes/No), risk factors for musculoskeletal diseases (0-10), psychosocial factors and fatigue (0-100), general health (0-100), and productivity (0-10). All secondary outcomes were measured at baseline and 12-month follow-up.

RESULTS

At the 12-month follow-up, both groups showed an increase in the number of working hours lost due to sick leave for musculoskeletal disease. There was no significant difference between the job rotation intervention group (mean deviation -5.6 hours, 95% CI -25.0 to 13.8) at the 12-month follow-up and the control group. There were no significant differences between groups for the secondary outcomes (p>0.05).

CONCLUSIONS

The job rotation programme was not effective in reducing the number of working hours lost due to sick leave, decreasing the prevalence of musculoskeletal symptoms, or improving perception of musculoskeletal pain and workplace risk factors, psychosocial risk factors and productivity.

TRIAL REGISTRATION NUMBER

NCT01979731.

Towards continuous and real-time attention monitoring at work: reaction time versus brain response

Continuous and objective measurement of the user attention state still represents a major challenge in the ergonomics research. Recently available wearable electroencephalography (EEG) opens new opportunities for objective and continuous evaluation of operators' attention, which may provide a new paradigm in ergonomics. In this study, wearable EEG was recorded during simulated assembly operation, with the aim to analyse P300 event-related potential component, which provides reliable information on attention processing. In parallel, reaction times (RTs) were recorded and the correlation between these two attention-related modalities was investigated. Negative correlation between P300 amplitudes and RTs has been observed on the group level (p < .001). However, on the individual level, the obtained correlations were not consistent. As a result, we propose the P300 amplitude for accurate attention monitoring in ergonomics research. On the other hand, no significant correlation between RTs and P300 latency was found on group, neither on individual level. Practitioner Summary: Ergonomic studies of assembly operations mainly investigated physical aspects, while mental states of the assemblers were not sufficiently addressed. Presented study aims at attention tracking, using realistic workplace replica. It is shown that drops in attention could be successfully traced only by direct brainwave observation, using wireless electroencephalographic measurements.

What is a 'good' job? Modelling job quality for blue collar workers. ERGONOMICS 2017;60:138-149. [PMID: 27005957 DOI: 10.1080/00140139.2016.1165870]

This paper proposes a model of job quality, developed from interviews with blue collar workers: bus drivers, manufacturing operatives and cleaners (n  =  80). The model distinguishes between core features, important for almost all workers, and 'job fit' features, important to some but not others, or where individuals might have different preferences. Core job features found important for almost all interviewees included job security, personal safety and having enough pay to meet their needs. 'Job fit' features included autonomy and the opportunity to form close relationships. These showed more variation between participants; priorities were influenced by family commitments, stage of life and personal preference. The resulting theoretical perspective indicates the features necessary for a job to be considered 'good' by the person doing it, whilst not adversely affecting their health. The model should have utility as a basis for measuring and improving job quality and the laudable goal of creating 'good jobs'. Practitioner Summary: Good work can contribute positively to health and well-being, but there is a lack of agreement regarding the concept of a 'good' job. A model of job quality has been constructed based on semi-structured worker interviews (n  =  80). The model emphasises the need to take into account variation between individuals in their preferred work characteristics.

Job rotation designed to prevent musculoskeletal disorders and control risk in manufacturing industries: A systematic review

To better understand job rotation in the manufacturing industry, we completed a systematic review asking the following questions: 1) How do job-rotation programs impact work-related musculoskeletal disorders (MSDs) and related risk control for these MSDs, as well as psychosocial factors? and 2) How best should the job rotation programs be designed? We searched MEDLINE, EMBASE, Business Source Premier, ISI Web of Knowledge, CINAHL, PsyINFO, Scopus, and SciELO databases for articles published in peer-reviewed journals. Eligible studies were examined by two independent reviewers for relevance (population of manufacturing workers, outcomes of musculoskeletal disorders, physical factors, psychosocial factors, and strategies used in job-rotation implantation) and methodological quality rating. From 10,809 potential articles, 71 were read for full text analysis. Of the 14 studies included for data extraction, two were non-randomized control trial studies, one was a case-control study, and 11 were cross-sectional comparisons. Only one, with a case-control design, was scored with good methodological quality. Currently, weak evidence exists supporting job rotation as a strategy for the prevention and control of musculoskeletal disorders. Job rotation did not appear to reduce the exposure of physical risk factors; yet, there are positive correlations between job rotation and higher job satisfaction. Worker training has been described as a crucial component of a successful job-rotation program. The studies reported a range of parameters used to implement and measure job-rotation programs. More rigorous studies are needed to better understand the full impact of job rotation on production and health.

PROSPERO REGISTER

CRD42014013319.

Preferred 11 different job rotation types in automotive company and their effects on productivity, quality and musculoskeletal disorders: comparison between subjective and actual scores by workers' age

This study investigates workers' favoured rotation types by their age and compares means between subjective and actual scores on productivity, quality and musculoskeletal disorders (MSDs). The subjects of research were 422 assembly line units in Hyundai Motor Company. The survey of 422 units focused on the workers' preference for 11 different rotation types and subjective scores for each type's perceived benefits, both by the workers' age. Then, actual scores on production-related indices were traced over a five-year period. The results suggest that different rotation types lead to different results in productivity, product quality and MSDs. Workers tend to perceive job rotation as a helpful method to enhance satisfaction, productivity and product quality more so than the actual production data suggests. Job rotation was especially effective in preventing MSDs for workers aged under 45, while its effects were not clear for the workers aged 45 years or older. Practitioner's Summary: This research presents appropriate rotation type for different age groups. Taking workers' age into account, administrators can use the paper's outcomes to select and implement the suitable rotation type to attain specific goals such as enhancing productivity, improving product quality or reducing MSDs.

Intervention development to reduce musculoskeletal disorders: Is the process on target?

Work related musculoskeletal disorders remain an intractable OHS problem. In 2002, Haslam proposed applying the stage of change model to target ergonomics interventions and other health and safety prevention activities. The stage of change model proposes that taking into account an individual's readiness for change in developing intervention strategies is likely to improve uptake and success. This paper revisits Haslam's proposal in the context of interventions to reduce musculoskeletal disorders. Effective MSD interventions require a systematic approach and need to take into account a combination of measures. Research evidence suggests that in practice, those charged with the management of MSDs are not consistently adopting such an approach. Consequently, intervention development may not represent contemporary best practice. We propose a potential method of addressing this gap is the stage of change model, and use a case study to illustrate this argument in tailoring intervention development for managing MSDs.

The relationship between physical workload and quality within line-based assembly

Reducing costs and improvement of product quality are considered important to ensure productivity within a company. Quality deviations during production processes and ergonomics have previously shown to be associated. This study explored the relationship between physical workload and real (found during production processes) and potential (need of extra time and assistance to complete tasks) quality deviations in a line-based assembly plant. The physical workload on and the work rotation between 52 workstations were assessed. As the outcome, real and potential quality deviations were studied during 10 weeks. Results show that workstations with higher physical workload had significantly more real deviations compared to lower workload stations. Static work posture had significantly more potential deviations. Rotation between high and low workload was related to fewer quality deviations compared to rotation between only high workload stations. In conclusion, physical ergonomics seems to be related to real and potential quality deviation within line-based assembly. Practitioner Summary: To ensure good productivity in manufacturing industries, it is important to reduce costs and improve product quality. This study shows that high physical workload is associated with quality deviations and need of extra time and assistance to complete tasks within line-based assembly, which can be financially expensive for a company.

A model for developing job rotation schedules that eliminate sequential high workloads and minimize between-worker variability in cumulative daily workloads: Application to automotive assembly lines

The aim of study is to suggest a job rotation schedule by developing a mathematical model in order to reduce cumulative workload from the successive use of the same body region. Workload assessment using rapid entire body assessment (REBA) was performed for the model in three automotive assembly lines of chassis, trim, and finishing to identify which body part exposed to relatively high workloads at workstations. The workloads were incorporated to the model to develop a job rotation schedule. The proposed schedules prevent the exposure to high workloads successively on the same body region and minimized between-worker variance in cumulative daily workload. Whereas some of workers were successively assigned to high workload workstation under no job rotation and serial job rotation. This model would help to reduce the potential for work-related musculoskeletal disorders (WMSDs) without additional cost for engineering work, although it may need more computational time and relative complex job rotation sequences.

The importance of work organization on workload and musculoskeletal health--Grocery store work as a model

We have evaluated the consequences of work organization on musculoskeletal health. Using a postal questionnaire, answered by 1600 female grocery store workers, their main work tasks were identified and four work groups were defined (cashier, picking, and delicatessen work, and a mixed group, who performed a mix of these tasks). The crude odds ratios (ORs) for neck/shoulder complaints were 1.5 (95% CI 1.0-2.2), 1.1 (0.7-1.5) and 1.6 (1.1-2.3), respectively, compared to mixed work. Adjusting for individual and psychosocial factors had no effect on these ORs. For elbows/hands, no significant differences were found. Technical measurements of the workload showed large differences between the work groups. Picking work was the most strenuous, while cashier work showed low loads. Quantitative measures of variation revealed for mixed work high between minutes variation and the highest between/within minutes variation. Combining work tasks with different physical exposure levels increases the variation and may reduce the risk of musculoskeletal complaints.

When is job rotation perceived useful and easy to use to prevent work-related musculoskeletal complaints?

Job rotation is often recommended to optimize physical work demands and prevent work-related musculoskeletal complaints, but little is known about possible facilitators and barriers to its usefulness and ease of use. Following a qualitative research design, semi-structured interviews with employers (n = 12) and workers (n = 11) from the construction industry were conducted. Organizational climate, job autonomy, job characteristics and work processes were mentioned as either facilitators or barriers on an organizational level. Worker characteristics, work behavior and attitude were mentioned as either facilitators or barriers on an individual level. Following a structured approach to assess usefulness of job rotation to optimize physical work exposures and identifying barriers to usefulness and ease of use in relevant stakeholder groups is necessary in order to select or develop strategies to overcome these barriers, or to reject job rotation as a useful or easy to use intervention in the given context.

Relationships between job organisational factors, biomechanical and psychosocial exposures

The relationships between work organisational, biomechanical and psychosocial factors were studied using cross-sectional data from a pooled dataset of 1834 participants. The work organisational factors included: job rotation, overtime work, having second jobs and work pace. Task and job level biomechanical variables were obtained through sub-task data collected in the field or analysed in the laboratory. Psychosocial variables were collected based on responses to 10 questions. The results showed that job rotations had significant effects on all biomechanical and most psychosocial measures. Those with job rotations generally had higher job biomechanical stressors, and lower job satisfaction. Overtime work was associated with higher job biomechanical stressors, and possibly self-reported physical exhaustion. Those having second jobs reported getting along with co-workers well. Work pace had significant influences on all biomechanical stressors, but its impact on job biomechanical stressors and psychosocial effects are complicated.

PRACTITIONER SUMMARY

The findings are based on a large number of subjects collected by three research teams in diverse US workplaces. Job rotation practices used in many workplaces may not be effective in reducing job biomechanical stressors for work-related musculoskeletal disorders. Overtime work is also associated with higher biomechanical stressors.