Identification of ergonomic issues that affect workers in oilrigs in desert environments.

The main objective of this research was to conduct an assessment of ergonomic-related problems in oilrigs in a desert environment. A checklist, physical audit and medical records were used in the investigation. The results showed significant health, environment and work-related problems that could be attributed to ergonomic deficiencies in the work system of the oilrig. Some major ergonomic issues identified were hard physical work, back pain, discomfort, hot environment, long shift, and diverse schedule. Ninety-four percent of the employees perceived the workday as very long, 79% were dissatisfied with the work schedule, while 61% of the employees perceived the summer work environment as extremely hot. Ergonomics should be considered in the work system design so as to reduce or eliminate problems in oilrigs in hot desert environments.     

Saddle seat reduces musculoskeletal discomfort in microsurgery surgeons

Background. Microsurgery is a surgical procedure requiring a high degree of precision and is commonly facilitated through the use of an intraoperative microscope. When operating the microscope system, the long-term posture leads to musculoskeletal disorders in surgeons, and seats are commonly employed to diminish these problems. The present study was conducted to evaluate musculoskeletal discomfort during work with a saddle seat in comparison with conventional seats for microscopic work. Methods. Two types of seats, a saddle and a conventional one, were evaluated for 73 microsurgical surgeons in terms of musculoskeletal discomfort. Corlett and Bishop's body part discomfort scale was used to assess musculoskeletal discomfort before and after working with the seats. Results. The highest amount of discomfort that microsurgical surgeons acquire in the workplace was focused on their neck, shoulders, arms and back. During work with a saddle seat, a significant reduction was found for discomfort values in the neck, shoulder, arm, back, elbow and forearm, as well as the whole body (p?<?0.05). Conclusion. This study showed that the use of saddle seats provides a more appropriate physical posture at work, and can decrease musculoskeletal discomfort in different parts of the body of microsurgical surgeons.     

Prediction of Musculoskeletal Discomfort in a Pick and Place Task (A pilot study)

A pilot study was conducted regarding the effects of working posture, handling frequency, and task duration on musculoskeletal discomfort. Participants rated their discomfort perceived while performing a repetitive task at 8 different combinations of manipulations. Pauses between the work periods lasted 15 min. Discomfort was rated according to Borg’s category-ratio scale CR-10 and postures were recorded by an optoelectronic movement registration system. From linear multiple regression analysis equations for predicting discomfort at various body regions were obtained. Coefficients of determination especially point to trunk inclination and handling frequency as major determinants of musculoskeletal discomfort.     

The Relationships Between Biomechanical and Postural Stresses,Musculoskeletal Injury Rates,and Perceived Body Discomfort Experienced by Industrial Workers: A Field Study

A combination of archival, subjective, and observational field data collection methods were used to investigate the relationship between biomechanical and postural stresses, and the resulting physical strain experienced by industrial workers of a packaging plant. Assessment of physical strain was based on the number and incidence rate of Occupational Safety and Health Administration (OSHA)-reportable injuries that were recorded over a period of 27 months, and based on the self-reported ratings of perceived body discomfort. Both the biomechanical and postural stresses correlated with the musculoskeletal injury rate. The results illustrate the usefulness of postural and biomechanical analyses for assessing the risk of injury in industry.     

Expert system application for prioritizing preventive actions for shift work: shift expert

Introduction. Shift patterns, work hours, work arrangements and worker motivations have increasingly become key factors for job performance. The main objective of this article is to design an expert system that identifies the negative effects of shift work and prioritizes mitigation efforts according to their importance in preventing these negative effects. The proposed expert system will be referred to as the shift expert. Methods. A thorough literature review is conducted to determine the effects of shift work on workers. Our work indicates that shift work is linked to demographic variables, sleepiness and fatigue, health and well-being, and social and domestic conditions. These parameters constitute the sections of a questionnaire designed to focus on 26 important issues related to shift work. The shift expert is then constructed to provide prevention advice at the individual and organizational levels, and it prioritizes this advice using a fuzzy analytic hierarchy process model, which considers comparison matrices provided by users during the prioritization process. An empirical study of 61 workers working on three rotating shifts is performed. After administering the questionnaires, the collected data are analyzed statistically, and then the shift expert produces individual and organizational recommendations for these workers.     

Physiological evaluation of chemical protective suit systems (CPSS) in hot conditions.

This job-related experiment investigated physiological strain in subjects wearing impermeable chemical protective suit systems (CPSSs) weighing about 28 kg. Two types of CPSSs were studied: the self-contained breathing apparatus was carried either inside or outside the suit. Eight healthy and physically fit male firefighter instructors aged 32 to 45 years volunteered for the study. The test drill, performed at a dry, windless ta of 40 degrees C, was divided into 2 consecutive work sessions of 14.5 min (a 20-min rest between) including typical operational work tasks. Considerable thermal and maximal cardiovascular strain and intense subjective discomfort measured in the firefighters emphasize the need to limit working time in hot conditions to only 10-12 min while wearing CPSSs. The present results indicate that the exceptionally heavy physical load and psychological stress during operations in chemical emergencies must be considered in the assessment of the cardiovascular capacity of ageing firefighters using CPSSs.     

Work-Related Musculoskeletal Disorders,Job Stressors and Gender Responses in Foundry Industry

The main aim of this paper was to identify job stressors, gender responses and association of psychosocial work stressors with prevalence of work related musculoskeletal disorders (MSDs) among foundry workers. The data were obtained with ergonomics checklist using Likert scale. The results of this study showed a high prevalence of MSDs among workers. The male workers were more prone to pain in neck while the female workers were more prone to MSDs in upper back and shoulders. Correlation analysis showed significant relationship of dimensions of work aspects with pain and discomfort. It proved that the work-related MSDs are the results of interaction of multiple stressors associated with work and work environment, and other personal factors. ANOVA indicated that the perception of work aspects as stressors differed significantly between male and female workers.     

Effect of Different Types of Rest-Break Interventions on Neck and Shoulder Muscle Activity,Perceived Discomfort and Productivity in Symptomatic VDU Operators: A Randomized Controlled Trial

Objective. This study evaluated the effect of different types of activities during rest-break interventions on neck and shoulder muscle activity, muscle discomfort and productivity among symptomatic video display unit (VDU) operators performing prolonged computer terminal work. Study design and setting. Randomized controlled trial was used. Thirty symptomatic VDU operators were randomly assigned to 2 active break groups (stretching and dynamic movement) and a reference group. The subjects performed the same typing task for 60 min and received 3-min breaks after each 20 min of work. Root mean square and median frequency were calculated for neck and shoulder muscle activity. Muscle discomfort was measured with Borg’s CR-10 scale. Productivity was measured by counting words. Results. There were no significant differences between the types of activities during breaks on neck and shoulder muscle activity, muscle discomfort or productivity. However, there was a significant difference in the level of muscle discomfort over time. Conclusions. Three types of activity during breaks showed a favourable effect on neck and shoulder muscle activity and productivity, and a positive effect on muscle discomfort in symptomatic VDU operators.     

Safety and human factors considerations in control rooms of oil and gas pipeline systems: conceptual issues and practical observations.

All oil and gas pipeline systems are run by human operators (called controllers) who use computer-based workstations in control rooms to "control" pipelines. Several human factor elements could contribute to the lack of controller success in preventing or mitigating pipeline accidents/incidents. These elements exist in both the work environment and also in the computer system design/operation (such as data presentation and alarm configuration). Some work environment examples include shift hours, shift length, circadian rhythms, shift change-over processes, fatigue countermeasures, ergonomics factors, workplace distractions, and physical interaction with control system computers. The major objective of this paper is to demonstrate the critical effects of human and organizational factors and also to highlight the role of their interactions with automation (and automated devices) in the safe operation of complex, large-scale pipeline systems. A case study to demonstrate the critical role of human organizational factors in the control room of an oil and gas pipeline system is also presented.     

A Whole Body Postural Loading Simulation and Assessment Model for Workplace Analysis and Design

Abstract

This study reports on the development and validation of a new computer model for simulating human postures at work, and assessing the reaction forces and bending moments in 43 human articulation joints. The proposed model estimates the intradiscal pressure in the vertebral column in response to external loading forces encountered during human interactions with work objects or processes. The model was implemented in a self-contained interactive software package. The simulation results compare favorably with the reported experimental data, and provide reasonable confidence in the quality of the model. Its characteristics and its applications in evaluating physical task performance are also discussed     

Ergonomics intervention on an alternative design of a spinal board

Nurses are often obliged to work in a 12-hr shift work system. We have decided to check whether such a working system constitutes an excessive load for nurses. On the basis of a questionnaire survey among nurses working in an 8-hr daytime shift system (169 nurses) and in a 12-hr shift (536 nurses), the amount of physical workload, work stress, and after-work activities were compared. Data analysis has shown that a 12-hr shift system is characterized by less significant physical workload but greater mental load. The nurses working in a 2-shift system were more tired after work, but they could spend more time on leisure activities and do housework. The data suggest that there are no significant contraindications for nurses to work in a 2-shift system.     

Perceived Discomfort and Electromyographic Activity of the Upper Trapezius While Working at a VDT Station

Ten female participants performed work at a video display terminal (VDT) station over a whole working day. Subjective local muscular fatigue was evaluated by means of the Category Ratio 10 scale. Electromyographic activity of the upper right and left trapezius was measured. A comparison was made between 5 participants who had previous complaints and 5 participants who reported no musculoskeletal problems in the shoulder-neck region. The subjective scores for the shoulder differed significantly between the two groups, being higher for the group with complaints. Both groups showed a decrease in discomfort after the lunch break. The activity of the trapezius increased significantly for both groups, in a more pronounced way for the group with disorders. Although it is found in literature that VDT work is a task with very low static loads, it seems from this study that the EMG activity increase can be an indication of muscle fatigue: More effort was required to accomplish the same VDT task at the end of the day.     

Work Content and Eye Discomfort in VDT Work

A questionnaire study of Swedish public employees with frequent and different types of VDT work (n = 2,025) was conducted. Eight different kinds of eye discomfort were examined, and an additive index was constructed. Eye discomfort was statistically related to aspects of work organization. The highest levels of discomfort were reported by computer-aided design (CAD), data entry, and word processing groups; groups with mixed VDT tasks displayed the lowest level of symptoms. Time spent at a VDT, low degree of work control, time pressure, and high pace of work were all associated with relatively high levels of eye discomfort. There was significant interaction between experience of stress and time spent at a VDT with respect to both the eye discomfort index and three specific symptoms (itching, gritty feeling, and dryness). Whereas dryness, smarting, and itching of the eyes seem most strongly related to work conditions, redness and watery eyes seem most weakly related.     

Validity and reliability of a job factors questionnaire related to the work tasks of physical therapists

Physical therapists engage in work tasks that expose them to occupational risk factors related to musculoskeletal disorders. Due to the gap in the literature on instruments focused on those workers, this study adapted a job factors questionnaire to physical therapists, and assessed its psychometric properties. The questionnaire was adapted and its content validity was established. The psychometric properties were evaluated among 142 physical therapists. Reliability was verified using the temporal-stability design and internal consistency. Construct validity was assessed with the known-groups technique. Test-retest results demonstrated intraclass correlation coefficients between .82 and .90 (p < .001). Cronbach's α of .91 verified the reliability of the questionnaire. The known-groups technique demonstrated a statistically significant difference on the scores of the items when physical therapists were compared to office workers. The results indicated that the adapted questionnaire had acceptable psychometric properties for assessing problematic job factors among physical therapists working in hospitals.     

Survey of discomfort glare from the headlamps of cars widely used in Iran

Objective: On 2-lane roads, discomfort glare can cause annoyance, discomfort, inconvenience, stress, and fatigue to drivers, posing a risk of accidents. The aim of this study is to evaluate discomfort glare from the headlamps of cars widely used in Iran.

Methods: The discomfort glare of new vehicles including Pride Saba model GTX, Pride Model 131SL, Samand Soren, Peugeot 405, Megane, and Peugeot Pars was examined at distances of 5 to 100 m at a background luminance of 50 cd/m² (late twilight/early dawn lighting) and 1 cd/m² (nighttime) using Schmidt-Clausen and Bindels model and de Boer's subjective scale.

Results: According to the de Boer scale, at a background luminance of 50 cd/m², the discomfort glare for all studied vehicles was between 1.98 and 4.05 in high-beam mode and between 3.5 and 5.4 in low-beam mode. At a background luminance of 1 cd/m², discomfort glare was between 0.41 and 2.48 in high-beam mode and between 1.93 and 3.84 in low-beam mode. In high-beam mode, the average levels of discomfort glare of these vehicles gradually increased when the distance between cars was reduced by up to about 20 m. In low-beam mode, there was no discomfort glare up to a vehicle distance of 40 m. In addition, at an angle of 1.15°–5.73° between the line of sight and light of vehicles in high-beam mode, the level of discomfort glare was increased, but at an angle of 5.73°–22.9° the level of discomfort glare was reduced. In low-beam mode at an angle of 2.86°–22.9°, the level of discomfort glare was almost identical. The results show that in high-beam mode and with a 100-m distance between vehicles as well as in low-beam mode at intervals of less than 40 m between cars, discomfort glare is created.

Conclusion: It can be concluded that by providing solutions such as installing road lighting system, an increase in luminance of roads, separating or widening road lanes, increasing the lateral distance between vehicles, and increasing the angle between lighted vehicles and drivers can noticeably reduce discomfort glare.     

基于AHP与重要性指标筛选的神经网络评价模型与应用

以对评价目标有影响的所有评价指标作为神经网络的输入,会导致网络模型复杂、降低其性能和影响计算精度的问题,因而提出基于层次分析法和重要性指标筛选法的神经网络评价建模方法即首先运用层次分析法对评价指标进行重要度排序,然后利用重要性指标筛选法过滤出对评价目标有重要影响的指标,以其结果作为神经网络的输入。该法不仅简化网络模型,而且提高网络的性能和计算精度。运用该法对企业安全工作评价,结果证明,不仅是可行的,而且达到了预期的目的。     

Physiological Method of Evaluating Protective Clothing for Work in a Cold Environment

The purpose of this study was to determine the usefulness of physiological studies in the evaluation of protective clothing for work in a cold environment. The study included the examination of the dynamics of changes in chosen physiological parameters (core and skin temperatures, heart rate, pulmonary minute ventilation) as well as physical ones (the temperature and relative humidity under the clothes) during work in protective clothing with unknown thermal insulation. The experiment was conducted in extreme environmental conditions (–10 and –15°C) at a work load defined by the clothing manufacturer as moderate. Results show that thermal equilibrium was achieved and maintained throughout the investigated work time (60 min) and that the protective clothing ensures safety on the time scale of a regular 8-hour work day. It was also shown that the dynamics of thermal stress physiological parameters can be used to determine the maximum duration of exposure for cold protective clothing with unknown thermal insulation.     

Effect of External Load at Varying Hand Positions on Perceived Discomfort

The purpose of this study was to assess the effect of external load at varying hand positions on discomfort, and to provide a new classification of external load. An experiment was carried out in which 16 postures with an external load of 0, 1.5, 3 kg were tested. The postures were controlled by 2 independent variables of hand distance and hand height. The subjects were instructed to rate their perceived discomfort with magnitude estimation after holding a given posture for 1 min. Analysis of variance (ANOVA) exhibited that the main effects of the 3 independent variables were statistically significant for discomfort. Discomfort increased linearly with external load and hand distance. Hand height showed a quadratic relation with discomfort, which exhibited a slightly different trend from hand distance and external load. Based on the results, a new classification of external load was proposed with 3 classes grouped by perceived discomfort.     

The Relationship Between Shift Work Schedules and Spillover in a Sample of Nurses

The aim of the present study was to estimate spillover effects between the work and the family sphere in a sample of nurses (N = 2058). Hierarchical regression analyses investigated whether shift work schedules were associated with negative or positive spillover, both from family to work and vice versa, controlling for demographic factors, job demands and decision latitude. With daytime work as a reference group, all types of shift work (day and evening shift, night shift only and rotating 3 shift) were associated with higher negative work-to-family spillover. Night work was associated with significantly less negative family-to-work spillover. None of the different shift work schedules were related to any type of positive spillover. The results indicate that working outside of daytime hours is less compatible with workers’ family lives, compared to working ordinary day shifts. On the other hand, working night shifts only was associated with reduced negative family-to-work spillover.     

Internal and External Factors Influencing Time-Related Injury Risk in Continuous Shift Work

Time-related accident risk in shift work may be attributed to internal factors, such as fatigue, level of performance, sleep propensity, and to some external factors, like shift system, physical and social environment. Six hundred and sixty-eight events in the metallurgical industry have been analysed in terms of time of day, time on task, consecutive day of the shift block, day of the week, and season.

The injury rate was similar on all shifts but more severe accidents happened in the nighttime. Somewhat more injuries occurred in the second half of the shift, in the second part of a shift block, and in summer compared with winter. There were fewer injuries at weekends.