An ergonomic expert system for risk assessment of work-related musculo-skeletal disorders

A computer-based expert system (SONEX) was developed to identify ergonomic risks for work-related musculoskeletal disorders (WRMSDs) in a wide variety of jobs and provide expert prevention advice. SONEX uses a rule base and 6 knowledge base modules: WRMSD risk factors are grouped into two main knowledge base modules (symptoms, engaged body part) with four supplementary knowledge base modules (work environment, work chair, work tools, organization factors). SONEX uses a menu-based interface and a series of simple questions that lead a user through each of the two main modules. Based on user responses it then recommends other knowledge base modules that are relevant for a detailed analysis of work risks. The SONEX rule base has over 140 questions, the knowledge base includes over 200 risk factors, and around 500 possible answers can be generated. SONEX relates ergonomic shortcomings in the job with worker's subjective symptoms; it predicts possible WRMSDs; and it offers preventive suggestions for ergonomic improvements to the job to prevent WRMSDs. It has been tested in a variety of work places with known ergonomic problems and with known employee WRMSDs by comparing its performance with conventional analytical methods and results show that it accurately predicts possible WRMSD risks and identifies ergonomic shortcomings. The advantages of SONEX are that it is much faster than other ergonomic analysis methods and it can be used by ergonomists and other professionals and also by workers themselves.     

Conceptions of dentists and dental nurses about ergonomics

Abstract

Sixty-eight dentists and 90 dental nurses, all working in a municipal dental care programme in the city of Helsinki, Finland, were surveyed by a questionnaire about their knowledge of and attitudes towards ergonomics. Thirty-three per cent of the dentists and 36% of the dental nurses were of the opinion that they were at present working according to ergonomic principles. Fifty-one per cent of the dentists and 45% of the nurses could not indicate any ergonomic problem in their place of work. Of the remainder the dental unit was mentioned by 62% of the dentists, and own or counterpart's working posture and habits by 44% of the nurses as the most frequent ergonomic problem. Training in dental ergonomics during undergraduate studies was significantly more general among the nurses than the dentists. Ergonomic knowledge and attitudes were found to correlate with each other, as well as knowledge of ergonomics with training in ergonomics and ergonomic working style, but only among the nurses. The results indicate that a dental team needs functionally-designed dental equipment and instruction in ergonomic principles applied to dentistry.     

Evaluation of a participatory ergonomic intervention process in kitchen work

We evaluated a participatory ergonomic intervention process applied in 59 municipal kitchens. In groups of three to five kitchens, the workers participated in eight workshops, and generated and evaluated solutions to optimize musculoskeletal load in their work. An ergonomist initiated and supported the process. By the end, 402 changes were implemented. Evaluative data were collected using research diaries, questionnaires, and focus group interviews. The intervention model proved feasible and the participatory approach was mostly experienced as motivating. The workers’ knowledge and awareness of ergonomics increased, which improved their ability to tackle ergonomic problems by themselves. The changes in ergonomics were perceived to decrease physical load and improve musculoskeletal health. As hindering factors for implementation, lack of time and motivation, and insufficient financial resources were mentioned. In addition, the workers expressed a wish for more support from the management, technical staff, and ergonomists.     

Contextual factors affecting task distribution in two participatory ergonomic interventions: a qualitative study

This article provides an analysis of the evolution of the division of labour in participatory ergonomics (PE) programmes in two worksites. The analysis is based on interviews and field observations in the worksites. In both settings there was meaningful participation by both worker and management members of ergonomic change teams (ECTs) in the hazard assessment and solution identification stages, but as the teams moved to the implementation stage, worker representatives were marginalised and the participatory nature of the programmes was severely curtailed. The removal of workers from the process was the outcome of the interplay among the type of activities pursued in the implementation stage, the skills and knowledge required to carry out those activities, and workers’ limited influence in the organisational hierarchies. Findings highlight the salience of the social context in which participatory programmes are located and the importance of examining participatory programmes as they evolve over time.

Statement of Relevance: This article contributes to a growing literature on the process and implementation of PE programmes. The article's focus on social and organisational factors that affect the division of labour and attention to the evolution of involvement over time extend current understandings of participation in ergonomics programmes.     

From theory to national application—A Finnish experiment

In 1968 the Finnish National Fund for Research and Development started a 3 year project to ‘introduce ergonomics into Finnish production’. A multidisciplinary group, comprising five persons sponsored by the Institute of Occupational Health, was formed.

The concept of ergonomics, at the time the project was founded, was relatively unknown in Finland, although as early as 1962 international course activity on the subject was begun at the Institute of Occupational Health. Little competent ergonomic knowledge existed in the realm of industry, which at that time claimed 500000 workers, and what did was poorly used.

The adopted strategy of the 3 year project was as follows: (a) an attempt was made to convince potential users of ergonomic knowledge of its utility by working out a number of examples on the application of ergonomics; and (b) the availability of ergonomic information was to be improved. By the time the project was completed in 1971, ergonomic activities had reached such a degree of acceptance that it was deemed necessary to maintain the multidisciplinary group and provide it with additional resources. These extended activities are outlined in this paper.     

Visually deficient working conditions and reduced work performance in office workers: Is it mediated by visual discomfort?

IntroductionThe main purpose of this cross-sectional study was to investigate whether visual discomfort acts as a mediating factor between perceived visual ergonomic working conditions and self-rated visual performance among office workers who carry out administrative tasks and computer-based work at the Swedish Tax Agency.MethodsA questionnaire was sent to 94 office workers addressing: 1) perceived visual quality of the visual display units; 2) prevalence of eye symptoms; and 3) self-rated visual performance. Eighty-six persons (54 women (63%), 31 men (36%), and 1 of unspecified sex) answered the questionnaire. Multiple regression analysis investigated the association between visual ergonomic working conditions and visual performance, both with and without visual discomfort as a mediator.ResultsThe group mean of the Indexed survey questions indicated a reasonably good quality of visual ergonomic working conditions, a relative absence of eye symptoms, and acceptable self-rated visual performance. Results from multiple regression analysis showed a significant association between perceived visual ergonomic working conditions and self-rated visual performance (r² = 0.30, β = 0.327, p < 0.01). When visual discomfort was used as a mediator, the association between perceived visual ergonomic working conditions and self-rated visual performance remained the same (r² = 0.32, β = 0.315, p < 0.01).DiscussionIt was remarkable to discover that self-rated visual performance was independent of visual discomfort. Possible explanations include exposure factors not included in the current study, such as dry air and sensory irritation in the eyes, psychosocial stress, time spent performing near work activities, or time exposed to visually deficient working conditions.Relevance to industryThe strong connection between satisfaction with visual ergonomic working conditions and productivity in this study has implications for workplace profitability and staff satisfaction. If productivity is enhanced by better visual ergonomic working conditions, then managers of workplaces may be able to improve work outcomes by optimizing the physical work environment.     

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

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

Team members' perceptions of online teamwork learning experiences and building teamwork trust: A qualitative study

Teamwork factors can facilitate team members, committing themselves to the purposes of maximizing their own and others' contributions and successes. It is important for online instructors to comprehend students' expectations on learning collaboratively. The aims of this study were to investigate online collaborative learning experiences and to identify important factors that were crucial for building teamwork trust. A qualitative research method was utilized in the study. Data were collected from students' responses of three open-ended questions and interviews. The results indicated that students who enjoyed working in the group setting had a good relationship with their team members and they trusted their team members. In contrast, the questionable behaviors of members (lack of communication and low level of individual accountability) were negative factors of their teamwork experiences. In addition, students considered individual accountability, familiarity with team members, commitment toward quality work, and team cohesion were important factors for building trust with team members. Quantitative analyses confirmed that teamwork trust was correlated significantly with two of the important factors for building trust indicated by team members: familiarity with members (r = .74) and team cohesion (r = .79). Implications and recommendations for future research were also discussed.     

Contextual factors affecting task distribution in two participatory ergonomic interventions: a qualitative study

This article provides an analysis of the evolution of the division of labour in participatory ergonomics (PE) programmes in two worksites. The analysis is based on interviews and field observations in the worksites. In both settings there was meaningful participation by both worker and management members of ergonomic change teams (ECTs) in the hazard assessment and solution identification stages, but as the teams moved to the implementation stage, worker representatives were marginalised and the participatory nature of the programmes was severely curtailed. The removal of workers from the process was the outcome of the interplay among the type of activities pursued in the implementation stage, the skills and knowledge required to carry out those activities, and workers' limited influence in the organisational hierarchies. Findings highlight the salience of the social context in which participatory programmes are located and the importance of examining participatory programmes as they evolve over time. STATEMENT OF RELEVANCE: This article contributes to a growing literature on the process and implementation of PE programmes. The article's focus on social and organisational factors that affect the division of labour and attention to the evolution of involvement over time extend current understandings of participation in ergonomics programmes.     

Behavioural change phases of different stakeholders involved in the implementation process of ergonomics measures in bricklaying

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

Musculoskeletal disorders in hospital nurses: a comparison between two hospitals

Nursing staff members of a urban general hospital (GH) and a small oncological department (OD) were surveyed to determine the prevalence of occupational related musculoskeletal disorders (MSDs), the specific disabilities, accidents at work, and working time lost. All subjects had a medical examination to evaluate osteoarthicular disease and selected cases were invited to X-ray examinations. The purpose of this study was to compare MSDs in the two groups of nurses working in two hospitals with different work organization in the same geographical area, Pordenone in Italy. In the previous year 48% GH and 33% OD nurses reported back pain due to work, 29·4 and 16·1% respectively have had X-ray or orthopaedic examinations, 19·2% and 9·1% had been away from work because of back pain. All these differences are statistically significant. The analysis of musculoskeletal pain sites and working tasks in the two hospital workers shows no differences in distribution. Great difference exists when analysing the numbers of patients assisted by a nurse: 0·57 and 1·27 nurse/patients respectively in GH and OD. Our data indicate a high overall frequency of occupational back pain, similar to other studies in Europe. The comparison between the two hospitals suggests factors associated with the disorder: work tasks and particularly nurses/patients ratio are more important factors than age and length of exposure. Different work distribution, shift organization, a better ratio between nurses and patients, an improvement of equipment provision, and specific nurse-training with application of ergonomic methods could improve work efficiency radically and decrease injury rates.     

Knowledge acquisition for the development of an upper‐body work‐related musculoskeletal disorders analysis tool

ERGO_X is a fuzzy expert system that supports workstation ergonomic analysis and provides advice on corrective measures aimed at improving the overall quality of the ergonomic design. ERGO_X was designed in a modular way to make further developments easier and to allow the selection of different ergonomic analysis contexts. The modularity feature mainly is a result of the knowledge base modular structure. Each module was built as a multilevel tree fuzzy relation. This relation reflects the interaction between attributes that are used to evaluate the level of severity of the relevant risk factors that are present at the analyzed workstation. The aim of this study is to address some aspects related to the knowledge acquisition process involved in the development of the ERGO_X knowledge base. In this regard, the author refers to her knowledge engineering activities in the development of a work‐related musculoskeletal disorder module. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 149–162, 2007.     

7 Themes for guiding situated ergonomic assessments of medical devices: A case study of an inpatient glucometer

There is relatively little guidance on the situated ergonomic assessment of medical devices, and few case studies that detail this type of evaluation. This paper reports results of a detailed case study that focuses on the design and use of a modern blood glucose meter on an oncology ward. We spent approximately 150 h in-situ, over 11 days and 4 nights, performing observations and interviews with users. This was complemented by interviews with two staff with oversight and management responsibility related to the device. We identified 19 issues with the design and use of this device. These issues were grouped into 7 themes which can help guide the situated study of medical devices: usability, knowledge gaps and mental models, workarounds, wider tasks and equipment, the patient, connection between services, and policy.     

深度还是广度？知识分布与群体结构对群组绩效的影响

研究在解决复杂系统决策问题时,群组的知识分布与群体结构两种关键特征对群体智能涌现的效果,即群组绩效的影响.提出基于群组合作网络的结构特征测度和基于决策要素的知识分布测度,群组结构主要包括链接强度以及网络的层次化或扁平化程度;知识分布根据知识的深度或广度衡量群组成员的构成类型:专才型群组、通才型群组以及混合型群组.采用基于适应度景观理论的连续时间马尔科夫链模拟群组解决复杂决策问题的能力.群组成员在自我利益(即对个体适应度提升的追求)和社会影响(即寻求与周围个体意见一致以达成共识)两种驱动因素下改变观点.研究表明:不平衡的知识分布会削弱群组绩效;群体结构会调节知识分布的影响作用;通才型群组在解决更加复杂问题时的表现明显优于专才型群组以及混合型群组;群组不应过分追求意见的一致性.     

Integrating ergonomics into engineering design: The role of objects

The objective of this study was to explore the role of objects in integrating ergonomic knowledge in engineering design processes. An engineering design case was analyzed using the theoretical concepts of boundary objects and intermediary objects: Boundary objects facilitate collaboration between different knowledge domains, while the aim of an intermediary object is to circulate knowledge and thus produce a distant effect. Adjustable layout drawings served as boundary objects and had a positive impact on the dialog between an ergonomist and designers. An ergonomic guideline document was identified as an intermediary object. However, when the ergonomic guidelines were circulated in the design process, only some of the guidelines were transferred to the design of the sterile processing plant. Based on these findings, recommendations for working with objects in design processes are included.     

Factors Supporting Knowledge Integration in Global Innovation Projects: An Exploratory Study

This exploratory study identifies the factors which contribute to effective knowledge integration in global innovation projects through an in‐depth analysis of two case studies. Knowledge integration is analysed in two components: knowledge (individual expertise), and integration (working together). Our analysis highlights three distinct ways that individuals think about individual expertise: individual knowledge and competence; feeling valued; and unfamiliar areas. We also identify four ways in which individuals think about working together: good social relations; cultural distance; negotiation skills; and better results through working with others. Using examples from the case studies, we discuss how these factors enable knowledge integration in globally distributed innovation projects. We also propose a model indicating how these factors impact on knowledge integration and innovation performance. This study contributes towards management guidance, which is currently lacking in the area of knowledge integration.     

Ergonomic studies in computer-aided design

Abstract

This paper describes the results of an ergonomic survey on interactive graphics workstations for computer-aided design (CAD). A work-sampling study was carried out to characterize the use of keyboard, digitizer tablet and video display. Subjective impressions of CAD software, CAD hardware and health aspects were collected by means of a questionnaire. Working methods and working postures were recorded on videotape. The two most important differences in comparison with other office terminals are: (i) dynamic working methods result in an absence of constrained postures in CAD operators and allow full-body exercise; (ii) CAD operators spend more time (46–68 per cent of working hours) viewing the video display than the average office terminal operator. Some ergonomic recommendations have been deduced for the construction of CAD terminals, as well as for the ergonomic improvement of existing workstations.     

Dutch Musculoskeletal Questionnaire: description and basic qualities.

A questionnaire ('Dutch Musculoskeletal Questionnaire', DMQ) for the analysis of musculoskeletal workload and associated potential hazardous working conditions as well as musculoskeletal symptoms in worker populations is described and its qualities are explored using a database of 1575 workers in various occupations who completed the questionnaire. The 63 questions on musculoskeletal workload and associated potentially hazardous working conditions can be categorized into seven indices (force, dynamic and static load, repetitive load, climatic factors, vibration and ergonomic environmental factors). Together with four separate questions on standing, sitting, walking and uncomfortable postures, the indices constitute a brief overview of the main findings on musculoskeletal workload and associated potentially hazardous working conditions. Homogeneity of the indices is satisfactory. The divergent validity of the indices is fair when compared with an index of psychosocial working conditions and discomfort during exposure to physical loads. Worker groups with contrasting musculoskeletal loads can be differentiated on the basis of the indices and other factors. With respect to the concurrent validity, it appears that most indices and factors show significant associations with low back and/or neck-shoulder symptoms. This questionnaire can be used as a simple and quick inventory for occupational health services to identify worker groups in which a more thorough ergonomic analysis is indicated.     

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

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