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

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

Flexible workspace design and ergonomics training: impacts on the psychosocial work environment, musculoskeletal health, and work effectiveness among knowledge workers

A macroergonomics intervention consisting of flexible workspace design and ergonomics training was conducted to examine the effects on psychosocial work environment, musculoskeletal health, and work effectiveness in a computer-based office setting. Knowledge workers were assigned to one of four conditions: flexible workspace (n=121), ergonomics training (n=92), flexible workspace+ergonomics training (n=31), and a no-intervention control (n=45). Outcome measures were collected 2 months prior to the intervention and 3 and 6 months post-intervention. Overall, the study results indicated positive, significant effects on the outcome variables for the two intervention groups compared to the control group, including work-related musculoskeletal discomfort, job control, environmental satisfaction, sense of community, ergonomic climate, communication and collaboration, and business process efficiency (time and costs). However, attrition of workers in the ergonomics training condition precluded an evaluation of the effects of this intervention. This study suggests that a macroergonomics intervention is effective among knowledge workers in office settings.     

Web-based office ergonomics intervention on work-related complaints: a field study

The aim of this study was a proof of concept to examine the effects of a web-based office ergonomics intervention on subjects' individual workplace adjustments. An intervention study was conducted with 24 office workers lasting 6 weeks with three consecutive phases (before, 1 and 5 weeks after the intervention). Employees used a purpose-made website for adjusting their computer workplaces without any personal support of ergonomics experts. Workplace measurements were taken directly on site and by analysing photos taken of the employee. Self-reported complaints were assessed by filling in a questionnaire. It was found that 96% of the employees changed their workplaces on their own and retained them mostly unchanged after the intervention. Furthermore, self-reported musculoskeletal complaints and headache symptoms decreased significantly after the intervention. These findings suggest an improvement of workplace conditions so that cost-effective ergonomic web-based interventions appear promising in further research and application.     

A model for solving work related musculoskeletal problems in a profitable way

Interventions against occupational musculoskeletal disorders are usually performed by ergonomists. An overview of the literature shows that ergonomists often are unsuccessful; musculoskeletal disorders may be prevalent at workplaces where large ergonomic resources have been put in, thus illustrating the significance of other factors in addition to those against which the intervention is applied. It is claimed that some modern rationalization strategies may offer a potential for 'good' ergonomics. Thus, prevailing management approaches often now focus on team building, flat organizations, training of multiple skills and so on. The main scope of the present issue of Applied Ergonomics is to throw light on this possibility of 'achieving ergonomics impact through management intervention'. This present paper presents a historical overview of occupational physical work load as a function of ergonomics, as well as rationalizations and concludes with a more elaborate discussion of the present intervention concept for solving work related musculoskeletal problems in a profitable way. Rationalization and guidelines for physical work load are the basic parameters in the present intervention concept. Due to this the present special issue also presents historical overviews of the development of these parameters (Westgaard and Winkel; Bjorkman). 'Achieving ergonomics impact through management intervention' is illustrated through two case studies (Kadefors et al and Bao et al). They demonstrate an obvious ergonomic potential offered by the presented intervention concept. However, the two case studies also describe several practical obstacles which need to be further investigated in future intervention research.     

The effects of an office ergonomics training and chair intervention on worker knowledge, behavior and musculoskeletal risk

A large-scale field intervention study was undertaken to examine the effects of office ergonomics training coupled with a highly adjustable chair on office workers’ knowledge and musculoskeletal risks. Office workers were assigned to one of three study groups: a group receiving the training and adjustable chair (n=96), a training-only group (n=63), and a control group (n=57). The office ergonomics training program was created using an instructional systems design model. A pre/post-training knowledge test was administered to all those who attended the training. Body postures and workstation set-ups were observed before and after the intervention. Perceived control over the physical work environment was higher for both intervention groups as compared to workers in the control group. A significant increase in overall ergonomic knowledge was observed for the intervention groups. Both intervention groups exhibited higher level behavioral translation and had lower musculoskeletal risk than the control group.     

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.     

Relationship between trapezius load and the incidence of musculoskeletal illness in the neck and shoulder

A relationship between m. trapezius load measured by electromyography (EMG) and the incidence of musculoskeletal illness in the neck and shoulder regions, was investigated both for assembly workers and VDT operators. For assembly workers, the static trapezius load (probability 0.1 of the amplitude probability distribution function, APDF) was significantly reduced from 4.3% MVC (Maximum Voluntary Contraction) to 1.4% MVC as a group median value after an ergonomic adaptation of their work places. Musculoskeletal sickleave was significantly reduced from 22.9 days to 1.8 days as a medium duration per-man-labour year for the same group.

Three groups of VDT operators were examined in terms of trapezius load and pain intensity and duration before and after an ergonomic intervention. All groups reported significant less intensity or duration of pain either in the neck or in the shoulder regions after the intervention. The trapezius load was reduced for all groups post vs. prior intervention. This reduction was measured in terms of a decrease in the static level of APDF and an increase in the number of periods per minute and total duration of muscle activity below 1% MVC. The results from this study indicate that the trapezius load may be a predictor for development of musculoskeletal illness in the neck and shoulder regions.     

Impact of a joint labor-management ergonomics program on upper extremity musculoskeletal symptoms among garment workers

This study evaluated the effect of an ergonomics intervention program on the prevalence and intensity of symptoms of upper extremity work-related musculoskeletal disorders among 36 garment workers performing an operation called spooling. Adjustable chairs were introduced and workers were trained in their use. Symptom surveys were administered prior to and 6 months after introduction of adjustable chairs. Quantitative pre- and post-intervention measurement of joint position was performed utilizing videotapes among a subgroup of nineteen. Eighty nine percent of the cohort reported pain in either the neck or at least one upper extremity anatomic site prior to the adjustable chair intervention. Among subjects reporting pain at baseline, there were significantly decreased pain levels in 10 of 11 anatomic sites after the intervention. Among all subjects, the proportion reporting pain decreased for each anatomic site following the intervention, with statistically significant decreases in 3 sites. However, there were only modest declines in awkward posture among the videotaped subgroup. This study suggests that introduction of an ergonomics program focused on education and introduction of an adjustable chair may diminish musculoskeletal symptomatology in apparel manufacturing workers.     

Prevention of musculoskeletal disorders at work: Validation and reliability in a multicenter intervention study

During the years 1986–1989 The Finnish Work Environment Fund initiated a multicenter, intervention study (programme) to prevent musculoskeletal disorders at work. The programme consisted of four different projects comprising methodological, epidemiological, and interventive themes. The main results were as follows: (1) More than half of the occupational physiotherapists and physicians involved in the project felt that they did not have adequate training for testing the performance capacity of the musculoskeletal system. Several of the most commonly used musculoskeletal tests had either poor validity in predicting future musculoskeletal troubles or had poor reliability. (2) A controlled intervention study showed that active training of neck-shoulder muscles can prevent musculoskeletal troubles, even more than ergonomic actions. (3) It is possible to reduce sick-leave due to low-back disorders by intervention measures directed toward both the work (environment, tools) and the workers (working methods, positive attitude to work, preparedness to keep fit). (4) The identification of ergonomic hazards with the help of teamwork proved to be feasible. The practical improvements, however, were difficult to implement in the prevailing conditions. Some of the improvements increased the work load and the stress of the workers. This aspect needs further consideration.     

The impact of ergonomics intervention on psychosocial factors and musculoskeletal symptoms among office workers

Musculoskeletal disorders have a multi factorial etiology that includes not only physical risk factors but also psychosocial factors. This study aimed to investigate psychosocial risk factors and musculoskeletal symptoms among office workers of an Iranian oil refinery and also to examine the subsequent effects of ergonomics intervention on musculoskeletal discomfort and psychosocial risk factors.In this study, 73 office workers as a case group and 61 office workers as a control group from an Iranian oil refinery plant were randomly selected and examined. The Nordic Musculoskeletal Disorders Questionnaire and the Persian version of the Job Content Questionnaire (P-JCQ) were used as collecting data tools before and after the interventional program.Low back problem (28.8%) was found to be the most common problem among the office workers. Significant differences found between prevalence rates of reported musculoskeletal in upper back, lower back and feet/ankle regions before and after intervention. Our findings showed that psychosocial variables were not affected by the intervention. The only variables on the P-JCQ that were significantly different pre/post intervention are the physical variables: physical job demands, physical exertion and physical isometric load. None of the other psychosocial variables were found to be significant. With the top management support, improvements in all office workstation components were made successfully.

Relevance to industry

Recently, changes in the nature of work draw increased attention to the relation between psychosocial factors and musculoskeletal disorders. The results of the current study indicate that a well conducted implementation of an interventional program can lead to a decrease in musculoskeletal symptoms and to some extent in the psychosocial factors at work.     

Implementation of a participatory ergonomics program in the rehabilitation of workers suffering from subacute back pain

This paper describes a participatory ergonomics program aimed at early return to regular work of workers suffering from subacute occupational back pain and assesses the perceptions of the participants on the implementation of ergonomic solutions in the workplace. The participatory ergonomics program was used in the rehabilitation of workers suffering from subacute back pain for more than 6 weeks, a program that was associated with an increased rate of return to work. The perceptions of the participatory ergonomics participants were assessed 6 months after completion of the ergonomic intervention through a questionnaire sent to employer representatives, union representatives and injured workers of participating workplaces. About half of the ergonomic solutions were implemented according to the perception of the participants, with a substantial agreement between respondents.     

University students’ notebook computer use

Recent evidence suggests that university students are self-reporting experiencing musculoskeletal discomfort with computer use similar to levels reported by adult workers. The objective of this study was to determine how university students use notebook computers and to determine what ergonomic strategies might be effective in reducing self-reported musculoskeletal discomfort in this population. Two hundred and eighty-nine university students randomly assigned to one of three towers by the university's Office of Housing participated in this study. The results of this investigation showed a significant reduction in self-reported notebook computer-related discomfort from pre- and post-survey in participants who received notebook computer accessories and in those who received accessories and participatory ergonomics training. A significant increase in post-survey rest breaks was seen. There was a significant correlation between self-reported computer usage and the amount measured using computer usage software (odometer). More research is needed however to determine the most effective ergonomics intervention for university students.     

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.     

The impact of ergonomic intervention on individual health and corporate prosperity in a telecommunications environment

This paper is a summary of several papers published in different journals and conference proceedings. The contents deal with the incidence of load related musculoskeletal illness of female workers exposed to various workloads. Furthermore, the changes in workload due to improved workplace design and the effect on the incidence of musculoskeletal illness was evaluated. The sick-leave due to musculoskeletal illness was reduced from 5·3% to 3·1% and the reduction in turn-over from 30·1% to 7·6%. The cost and the benefits of this ergonomic intervention were analysed, and showed that an investment of NOK. 350 000 produced total savings of NOK. 3 200 000.

Postural load was assessed by recording electromyography (EMG) on the upper part of musculus trapezius, postural angles of the upper arm and flexion/extension of the head and back. A quantitative relationship was found between the static trapezius load and the development of musculoskeletal sick-leave, related to the length of employment. Indications were found that certain factors were associated with reduced incidence of musculoskeletal illness. These were:

? increasing the number and total duration of trapezius load below 1% to 2% MVC (Maximum Voluntary Contraction);

? reducing the magnitude of flexion angle of the upper arm in the sagittal plane and distributing the work between flexors and extensors; and

? a more dynamic work pattern of the upper arm.

The relationship between postural load and musculoskeletal injury was studied in comparable groups of female workers with respect to age, working hours per day and time of employment. Psychosocial problems, spare time activities and living habits of the workers did not show any significant differences across the groups. The results from this study indicate that:

? the static trapezius load must be kept at a minimum;

? a median arm flexion should be less than 15° and a median arm abduction less than 10°. These values seem roughly to approach an acceptable arm position; and

? a forward median flexion of the back of less than 20° seems not to lead to a higher rate of low back pain for workers with long periods of employment.     

A corporate workplace model for ergonomic assessments and improvements

Several companies have developed their own company-specific models for ergonomic improvements. This study aims to describe and identify factors supporting and hindering the implementation and application of one such corporate model for ergonomic assessment and improvement. The model has been developed by Volvo Car Corporation and implemented at an assembly plant in G?teborg, Sweden. The model is unique as it is intended to be used by production engineers and safety representatives in cooperation. The process for assessment of musculoskeletal risks is standardised and participatory, which also supports identification of solutions. Interviews, questionnaires, observation and document studies were used to evaluate the use of the model. The model was found to improve participation and collaboration among stakeholders; provide a more effective ergonomic improvement process; visually represent the ergonomics situation in the company; and give legitimacy to and awareness of ergonomics. However, the model was found to be rather resource demanding and dependent on support from management and unions. In particular, a substantial training programme and regular use of the model are needed.     

Reducing musculoskeletal disorders among computer operators: comparison between ergonomics interventions at the workplace

Typing is associated with musculoskeletal disorders (MSDs) caused by multiple risk factors. This control study aimed to evaluate the efficacy of a workplace intervention for reducing MSDs among computer workers. Sixty-six subjects with and without MSD were assigned consecutively to one of three groups: ergonomics intervention (work site and body posture adjustments, muscle activity training and exercises) accompanied with biofeedback training, the same ergonomics intervention without biofeedback and a control group. Evaluation of MSDs, body posture, psychosocial status, upper extremity (UE) kinematics and muscle surface electromyography were carried out before and after the intervention in the workplace and the motion lab. Our main hypothesis that significant differences in the reduction of MSDs will exist between subjects in the study groups and controls was confirmed (χ² = 13.3; p = 0.001). Significant changes were found in UE kinematics and posture as well. Both ergonomics interventions effectively reduced MSD and improved body posture.

Practitioner Summary: This study aimed to test the efficacy of an individual workplace intervention programme among computer workers by evaluating musculoskeletal disorders (MSDs), body posture, upper extremity kinematics, muscle activity and psychosocial factors were tested. The proposed ergonomics interventions effectively reduced MSDs and improved body posture.     

Assessing the effects of positive feedback and reinforcement in the introduction phase of an ergonomic intervention

Resistance to change is common in ergonomic interventions, often resulting in negative consequences when the intervention's effectiveness is studied. A lab-based study assessed the effects of positive reinforcement during the intervention process. On Day 1 all participants performed a simple screw-driving task that placed stress on the cervicobrachial region through static loading. On Day 2 a control group received basic information about ergonomics and then performed the task using an ergonomic intervention that has been shown to reduce loading on these muscle groups. The experimental group received the same basic information but also received positive reinforcement while performing the task with the ergonomic intervention. Subjective task assessment surveys and body-part discomfort surveys were administered, and these, along with speed of performance, were assessed in both groups. The results showed a significantly (p < .05) more positive subjective impression of the intervention for the feedback group than for the control group (29%-57% improvement) with no real changes in either the performance or discomfort levels. Applications of this research include improving workers' acceptance of ergonomic interventions in industrial and other settings. The reinforcement technique evaluated in this paper has yielded consistently positive effects in our ongoing ergonomic intervention research.     

Improving meat cutters' work: Changes and effects following an intervention

Meat cutters face higher risks of injury and musculoskeletal problems than most other occupational groups. The aims of this paper were to describe ergonomics changes implemented in three meat cutting plants and to evaluate effects related to ergonomics on the individual meat cutters and their work. Data was collected by interviews, observations, document studies and a questionnaire (n = 247), as a post intervention study. The changes implemented consisted of reducing knife work to a maximum of 6 h per day and introducing a job rotation scheme with work periods of equal length. Tasks other than traditional meat cutting were added. A competence development plan for each meat cutter and easy adjustment of workplace height were introduced. The questionnaire showed a reduction in perceived physical work load. In general, the changes were perceived positively. Figures from the company showed a positive trend for injuries and sick leave.     

The effects of occupational interventions on reduction of musculoskeletal symptoms in the nursing profession

The objective of the review was to gain more insight into the effects of occupational interventions for primary prevention of musculoskeletal symptoms in healthcare workers. The Cochrane Collaboration methodological guidelines for systematic reviews functioned as a starting point. Thirteen studies meeting the inclusion criteria were analysed for methodological quality and effects. Eight outcome effect areas were established and defined as areas in which an effect had been determined in at least two studies. A method based on levels of scientific evidence was then used to synthesize the information available. Strong scientific evidence for the beneficial effect of occupational interventions was found for the outcome effect areas physical discomfort, technical performance of transfers and frequency of manual lifting. Insufficient evidence was found for the effect areas absenteeism due to musculoskeletal problems, musculoskeletal symptoms, fatigue, perceived physical load and knowledge of risk factors at work and ergonomic principles. Training and education combined with an ergonomic intervention were found to be effective.     

The effects of occupational interventions on reduction of musculoskeletal symptoms in the nursing profession

The objective of the review was to gain more insight into the effects of occupational interventions for primary prevention of musculoskeletal symptoms in healthcare workers. The Cochrane Collaboration methodological guidelines for systematic reviews functioned as a starting point. Thirteen studies meeting the inclusion criteria were analysed for methodological quality and effects. Eight outcome effect areas were established and defined as areas in which an effect had been determined in at least two studies. A method based on levels of scientific evidence was then used to synthesize the information available. Strong scientific evidence for the beneficial effect of occupational interventions was found for the outcome effect areas physical discomfort, technical performance of transfers and frequency of manual lifting. Insufficient evidence was found for the effect areas absenteeism due to musculoskeletal problems, musculoskeletal symptoms, fatigue, perceived physical load and knowledge of risk factors at work and ergonomic principles. Training and education combined with an ergonomic intervention were found to be effective.