Workplace Design for Manual Assembly Tasks: Effect of Spatial Arrangement on Work-Cycle Time

This article reports the results of an experimental study undertaken to investigate the effect of spatial arrangement of assembly board and parts bin in the normal work area on work-cycle time in manual assembly tasks. Operator performance was measured in terms of average work-cycle time taken to complete a laboratory-simulated manual assembly task. Results showed that both location and distance factors had significant effects on work-cycle time. Effect of the size of parts was also investigated in the study. Average observed work-cycle times were compared with the methods–time measurement (MTM) values. Repetitive manual assembly tasks are common in industry and are thought to lead to musculoskeletal disorders. The results of this research are important for ergonomic design of the workplace for assembly tasks, which would help to enhance operators’ efficiency.     

船舶操控台控制界面人机工程设计标准研究

为了探讨船舶操控台控制界面人机工程设计标准制定的必要性和标准化建议,采用文献分类、汇总和分析的方法,对国内外控制界面人机工程设计标准的现状及船舶操控台控制界面人机工程设计标准化对象进行深入分析.当前针对控制界面的通用标准在应用于船舶操控台时,需要进行具体化和进一步细化,船舶控制界面应进行功能分组,控制界面上各装置应与操...     

Psychosocial and Ergonomic Factors,and Their Relation to Musculoskeletal Complaints in the Swedish Workforce

A random sample of 1 000 subjects (20–65 years old) from the national population of Sweden received a questionnaire; 70% (n = 695) replied, of whom 532 were occupationally active. Female gender, working with neck and/or body bent forward, arms above shoulders, and precision work tasks were predictors of musculoskeletal symptoms. Neck, shoulder, and upper back symptoms were more common in a strained situation at work (high demands, low control) (adjusted odds ratios [adjOR] 2.76, 2.80, and 2.26, respectively). Among females, neck and shoulder symptoms were more common in an iso-strain situation (high demands, low control and low social support) (adjOR 4.43 and 3.69, respectively), and low back symptoms were more common at low social support combined with a passive work situation (adjOR 3.35). No associations were found between iso-strain model and symptoms among males. In conclusion, iso-strain work situation was associated with neck symptoms among females, even when controlling for ergonomic factors.     

Electromagnetic Action of Heavy-Current Equipment Operating With Power Frequency

The paper presents an analysis of the effect of magnetic fields of power frequency generated by heavy-current electric equipment on the environment. The results of computation and measurements of the magnetic field in the vicinity of power busducts are included. Possible hazards are considered that result from the effects of the magnetic field on workers present in the vicinity of busducts as well as secondary hazards caused by the degrading effect of the magnetic field on ferromagnetic structural materials (in reinforced concrete structures). Attention is given to an ergonomic aspect of interaction of the magnetic field with cathode ray tube computer monitors (annoying oscillation of the image).     

Sitting Comfort of Ergonomic Office Chairs—Developed Versus Intuitive Evaluation

The sitting comfort of office chairs with different ergonomic layouts (inferior, superior) was examined. Fifty participants were randomly assigned to a 2 × 5 factorial experimental design with 2 different conditions of ergonomic chair layout (inferior or superior) and 5 different conditions of instruction to explore the chair. Four conditions were created to differentiate between various levels of perceptual awareness and processing of chair-related information (guided exploration and developed evaluation). In a 5th condition, participants remained uninstructed (free exploration and intuitive exploration). Under guided exploration, the participants’ perception of sitting comfort was in line with objective differences in the chair layout. Different conditions of guided exploration, however, did not influence the evaluations. Under free exploration, the participants’ perceptions did not match the ergonomic chair layout. In contrast to participants under guided exploration, they even rated the ergonomically inferior office chair more favourably than the ergonomically superior chair.     

Ergonomic design and evaluation of a diagnostic ultrasound transducer holder

Background. Work-related musculoskeletal disorders (WMSDs) are injuries and disorders that affect the body’s movement and musculoskeletal system. Awkward postures represent one of the major ergonomic risk factors that cause WMSDs among sonographers while working with an ultrasound transducer. This study aimed to design and evaluate a new holder for the ultrasound transducer. Materials and methods. In the first phase a new holder was designed for the transducer, considering design principles. Evaluation of the new holder was then carried out by electrogoniometry and a locally perceived discomfort (LPD) scale. Results. The application of design principles to the new holder resulted in an improvement of wrist posture and comfort. Wrist angles in extension, flexion, radial deviation and ulnar deviation were lower with utilization of the new holder. The severity of discomfort based on the LPD method in the two modes of work with and without the new holder was reported with values of 1.3 and 1.8, respectively (p?<?0.05). Conclusion. Overall, this study indicated that applying ergonomics design principles was effective in minimizing wrist deviation and increasing comfort while working with the new holder.     

The Effect of an Ergonomic Intervention on Musculoskeletal,Psychosocial and Visual Strain of VDT Entry Work: Organization and Methodology of the International Study

This special issue of the International Journal of Occupational Safety and Ergonomics (JOSE) reports the results from an extensive multinational and multidisciplinary collaborative investigation of the impacts on visual display terminal (VDT) work of musculoskeletal, visual, ergonomic, and psychosocial factors. For brevity, this effort has been referred to as the MEPS project (musculoskeletal—eyestrain—psychosocial—stress). This paper lays out the basic methodological structure of the study. The study was conducted in 4 countries utilizing VDT data entry workers as the primary subject population. A battery of objective and subject assessment measures, including muscle load, visual function, physical and visual strain, postural, ergonomic and psychosocial factors, were assessed at 3 different points in time. A pre-test was given prior to an ergonomic intervention. Two post-tests were given 1 month and 1 year after the ergonomic intervention.     

An Ergonomics Study of a Semiconductors Factory in an IDC for Improvement in Occupational Health and Safety

The study aimed to conduct an ergonomic intervention on a conventional line (CL) in a semiconductor factory in Malaysia, an industrially developing country (IDC), to improve workers’ occupational health and safety (OHS). Low-cost and simple (LCS) ergonomics methods were used (suitable for IDCs), e.g., subjective assessment, direct observation, use of archival data and assessment of noise. It was found that workers were facing noise irritation, neck and back pains and headache in the various processes in the CL. LCS ergonomic interventions to rectify the problems included installing noise insulating covers, providing earplugs, installing elevated platforms, slanting visual display terminals and installing extra exhaust fans. The interventions cost less than 3 000 USD but they significantly improved workers’ OHS, which directly correlated with an improvement in working conditions and job satisfaction. The findings are useful in solving OHS problems in electronics industries in IDCs as they share similar manufacturing processes, problems and limitations.     

Epidemiological and biomechanical evaluation of airline baggage handling

Objectives. Musculoskeletal disorders (MSDs) are prevalent among airline baggage handlers due to manual materials handling. In this study, the Nordic musculoskeletal questionnaire (NMQ), the revised National Institute for Occupational Safety and Health (NIOSH) lifting equation, and the University of Michigan 3D Static Strength Prediction Program? (3DSSPP) were used to analyze MSDs among baggage handlers. Methods. The NMQ was filled out by 209 baggage handlers and 46 arbitrarily selected baggage handlers were evaluated using the NIOSH method and 3DSSPP. Results. The obtained results showed that the most common MSDs occurred in the lower back region. The next risky regions included knees, neck, and upper back, respectively. The NIOSH results confirmed that the subjects lifted loads heavier than the permitted limit and their lifting postures were inappropriate. The results of the 3DSSPP also indicated that compression forces exceeded the NIOSH limit in these awkward postures. Conclusions. Relying on this study, holding compulsory ergonomic lifting training courses could be proposed for workers and regulations adjusting an upper limit for maximum baggage weight must be also enacted in order to improve occupational health and prevent the prevalence of increasing MSDs.     

Comparisons of ergonomic evaluation tools (ALLA,RULA, REBA and OWAS) for farm work

Introduction. The purpose of this study was to validate the agricultural lower limb assessment (ALLA) ergonomic checklist, which was developed for various agricultural tasks in Korea. Methods. One hundred and ninety-six working postures were selected from the real agricultural tasks to verify ALLA, a lower limb body posture assessment tool, and then evaluated by 16 ergonomic experts. Hit rate, quadratic weighted κ, one-way analysis of variance and t-test analyses were applied to compare ALLA with other assessment tools. Results. ALLA analysis had a superior hit rate with ergonomic expert assessment compared with other assessment tools. Quadratic weighted κ analysis also showed that ALLA provided superior estimates of risk levels for farm working postures. Discussion. ALLA would be an appropriate assessment tool to estimate risk factors for various lower limb body postures which frequently occur in agricultural tasks in Korea. ALLA is a simple and accurate risk assessment tool that could be usefully applied to identify and mitigate risk factors and work-related musculoskeletal disorders in agricultural tasks, and also to evaluate the effects of control and intervention for working conditions.