合理构建视频显示终端(VDT)作业疲劳工间休息制度

为了减少VDT(视频显示终端)作业对操作者健康的负面影响,合理地安排工作和休息时间以及设计良好的工作环境有助于减轻、缓解或消除VDT作业的疲劳。通过多项VDT数据输入作业实验,依据作业者作业能力变动的规律性,对不同类型的VDT作业者可能需要设置不同的工间休息制度。经过对实验数据的分析,数据输入的工作主要是信息接受和信息输出,属于事务性脑力劳动。只要合理地安排工作和休息时间以及设计良好的工作环境,就可以减少VDT对眼睛、骨骼及肌肉的疾患发生。     

Work environment and the well-being of clerical and VDT workers

This paper explores the relationships between extent of video display terminal usage, perceptions of the physical work environment, task characteristics, and workers' health and well-being among a group of 1032 female office clerical workers. Data are drawn from responses to a 30-minute questionnaire administered at four employment sites during 1981 and 1982. All-day terminal users reported significantly higher levels of job and physical environment stressors than part-day VDT users, typists and non machine-interactive clerical workers. Reports of musculo-skeletal strain and dissatisfaction were also highest among all day terminal users. Part-day VDT users, typists and clerks all reported relatively similar levels of job and physical working conditions, health symptoms and job satisfaction. No significant differences between any of the groups were observed for gastrointestinal, respiratory, psychological and other non-specific health complaints. Typists and clerical workers who also held supervisory positions reported fewer stressors and greater job satisfaction than workers with no supervisory tasks; however there were no such differences between supervisors and non-supervisors engaged in all-day VDT work. Implications of these findings for further research and for job redesign strategies to alleviate the potentially stressful aspects of office automation are discussed.     

The effect of an ergonomic intervention on musculoskeletal, psychosocial and visual strain of VDT data entry work: the Norwegian part of the international study.

The Norwegian MEPS (musculoskeletal--visual--psychosocial--stress) study included 3 groups: data entry, data dialogue (female) and data dialogue (male). Before intervention, the data entry group reported significantly more symptoms and signs of musculoskeletal illness and had longer periods in front of the video display terminal (VDT) without a break. The ergonomic intervention consisted mainly of ergonomic information and training. After intervention, the data dialogue female group reported a significant reduction in shoulder pain in parallel with a reduction in trapezius load. Increasing the understanding in how to adjust the work stand and chair may have been contributing factors to reducing the pain level. There was a significant reduction in eye problems in all groups; the greatest reduction in eye symptoms was seen in the groups who had new optometric corrections.     

Characteristics of Muscular Load in Computer Data Entry Workers Assessed by EMG and Postural Angles

The goal of this study was to characterize the muscular load in computer data entry workers. Electromyography (EMG) parameters of trapezius muscle and postural angles of head, arm, and back were chosen as indicators of musculoskeletal load. The examination was done according to the methods and protocol of international MEPS studies (the “Musculoskeletal, Visual, and Psychosocial Load in VDT [Video Display Terminal] Operators in Optimized Environment” international program). The musculoskeletal load during routine VDT data entry work performed by a group of 36 women was assessed on the basis of 1-hr physiometer recordings. Results show that the musculoskeletal load associated with data entry is relatively high compared to other VDT operators’ tasks described in the literature. An analysis of the measured parameters shows that most of the time women worked with a muscular load higher than optimal. It is postulated that the main reason for the heavy musculoskeletal load was improper posture compelled by unergonomic spatial configuration of work stands.     

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.     

基于疲劳模式识别的VDT作业工间休息机制*

为保障作业人员身心健康和作业效率,运用E-Prime软件模拟认知性VDT持续作业,通过方差分析提出作业疲劳综合评价指标体系,并使用客观绩效指标和生理指标作为输入变量,主观疲劳综合指数作为输出变量,训练BP神经网络,对作业疲劳进行模式识别;提出认知性VDT持续作业工间休息机制。结果表明:通过正确反应时间、注视时间、瞳孔直径、眨眼频率4项指标,对VDT持续作业疲劳进行模式识别的结果可信度较高。因此,基于上述4项指标提出的工间休息机制客观有效。     

Will Musculoskeletal,Visual and Psychosocial Stress Change for Visual Display Unit (VDU) Operators When Moving From a Single-Occupancy Office to an Office Landscape?

This study investigated the effect of moving from single-occupancy offices to a landscape environment. Thirty-two visual display unit (VDU) operators reported no significant change in visual discomfort. Lighting conditions and glare reported subjectively showed no significant correlation with visual discomfort. Experience of pain was found to reduce subjectively rated work capacity during VDU tasks. The correlation between visual discomfort and reduced work capacity for single-occupancy offices was r_s = .88 (p = .000) and for office landscape r_s = .82 (p = .000). Eye blink rate during habitual VDU work was recorded for 12 operators randomly selected from the 32 participants in the office landscape. A marked drop in eye blink rate during VDU work was found compared to eye blink rate during easy conversation. There were no significant changes in pain intensity in the neck, shoulder, forearm, wrist/hand, back or headache (.24 < p < .67). Pain levels in different body areas were significantly correlated with reduced work capacity, .77 < r_s < .99 (p = .000).     

Dimensions of Job Control in Computerized and Traditional Office Work and Its Health Effects

This study investigates whether a consistent relationship exists between computerization and job control. It also examines the role of job control as a predictor of stress symptoms typical for data entry and word processing (VDU) work. Two groups of VDU users and two comparable non-VDU-user groups took part in this study. A special questionnaire made it possible to assess global job control and four indexes of control related to specific aspects of work (control over choice of tasks and methods, control over time frame, control related to one’s skill, and control related to participation in the decision-making process). Results did not show an unequivocal relation between computerization and the latitude of control. The latitude of control depends on the task performed and the aspect of control we are considering. Regression analyses showed that global control is a good predictor of job satisfaction, some mood disturbances, and visual complaints. The other aspects of control are related in a variety of ways to stress symptoms. The role of a Type A behavior pattern in the relationship between job control and stress symptoms varies depending on which aspect of control is being considered. It was concluded that because of the high functional differences between various aspects of control, it is better to avoid using the concept of global control and, when possible, apply specific indexes of control.     

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.     

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.     

Safety Level of Acrobatic Work: A Probabilistic Study

Acrobatic work constitutes an activity during which individuals intervene on buildings, cliffs, towers, and so forth, through the use of mountaineering or speleological techniques. The most dangerous situations occur particularly when ascending a rope with ascenders or roping with a descender. Any free fall or false manoeuvre will result in a strong shock on the belaying system that may cause its rupture. The fatal accident rate (FAR) of a given occupation is defined as the average number of fatal accidents per 10⁸ hrs of exposure to a given hazard. In this study it is assumed that the FAR is proportional to the average number of fall-initiating events, η, per worker and per hour of exposure to the fall hazard. η is estimated to be between 10^-3 and 3 × 10^-3. The maximum values of the rupture probability of the securing systems are calculated for the FAR of acrobatic work to be smaller than the FAR of the three most dangerous activity groups of the construction industry in France. These values allow the varying ranges of the parameters that influence this rupture probability to be determined.     

Visual Strain and Lighting Preferences of VDT Users Under Different Lighting Systems

Lighting influences users’ visual strain and well-being. Therefore creating lighting that ensures visual work conditions do not result in visual fatigue is a preventive activity. The aim of the study was to model different lighting systems for visual display terminal (VDT) work and to determine their influence on users’ visual strain and preferences. The results of the study showed that visual fatigue was lowest for indirect and compound lighting systems. On the other hand, in general, direct lighting realized by “dark-light” luminaires was the most preferred lighting system. Some interesting differences related to age, gender, and VDT work experience were found. On the basis of the obtained results lighting designers can be provided with some guidance.     

视屏显示终端对精神心理和神经行为的影响

本文进行了视屏显示终端(VDT)对操作人员精神心理和神经行为影响的调查研究。初步显示VDT作业可对操作人员造成情绪、感知、记忆、操作及复合功能诸多方面的不良影响。通过职业应激源的调查评价,显示VDT作业本身独特的作业性质、环境和要求形成了VDT作业的主要应激源。对从事VDT作业时间较长和作业负荷较大者则产生较高的职业性紧张度。从而说明VDT作业引起操作人员的某些心身疾患的可能性。     

时间压力视角下人格特征与VDT视觉搜索绩效的关系及形成机理*

为合理选拔和培训特定情境下的视觉搜索安检人员,从时间压力视角分析大五人格特征与视觉显示终端（visual display terminal,VDT）的视觉搜索绩效的关系。通过变量分析和设计,提出VDT视觉搜索绩效影响因素理论模型;运用Visual Studio设计实验模拟视觉搜索安检任务,采集绩效及眼动数据;最后进行有中介的调节模型检验。研究结果表明:不同人格特征的VDT视觉搜索绩效存在差异;所有人格特征的搜索策略随机指数随时间压力的增加而降低,但调整强度在不同人格特征之间存在差异,严谨性人格调整幅度最大;时间压力通过搜索策略的中介作用（部分）间接调节人格特征与VDT视觉搜索绩效的关系;较高和较低时间压力下,严谨性人格通过有效的搜索策略调整,绩效最好;中等时间压力下,开放性人格的绩效最好。研究结果可为视觉搜索作业人员的选拔和培训提供理论依据。     

Musculoskeletal Symptoms In Workers

Self-report measures of musculoskeletal discomfort are a widely used and generally accepted risk factor for musculoskeletal disorders in epidemiologic research. The aim of this study was to investigate the prevalence of musculoskeletal symptoms in packing workers. A cross-sectional study of 75 workers was carried out using a modified Nordic questionnaire. Prevalence was determined with the percentage of positive responses to questions on musculoskeletal symptoms. Odds ratios and 95% confidence intervals were the measures of association between prevalent musculoskeletal symptoms and demographic factors; they were determined with logistic regression. Most musculoskeletal symptoms in workers were from the low back (44.0%), shoulders (33.3%) and neck (32.0%). Years worked were strongly significantly associated with musculoskeletal symptoms and pain in the neck, shoulders and wrists/hands, P< .001-.050. Hazards related to repetitive movements and discomfort postures could be reduced with stretching exercises, rotation schedules and through new engineering solutions.     

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.     

A cross-country comparison of short- and long-term effects of an ergonomic intervention on musculoskeletal discomfort, eyestrain and psychosocial stress in VDT operators: selected aspects of the international project.

Three groups of data entry female visual display terminal (VDT) workers from Norway (n = 30), Poland (n = 33) and the USA (n = 29) were compared. Before intervention, the Norwegian group reported more neck pain compared with the Polish group. The Polish group reported less shoulder pain than both the U.S. and the Norwegian groups. The clinical examination documented fewer symptoms and signs of musculoskeletal illness among the Polish participants compared with the Norwegian and the U.S. groups. After intervention, the Norwegian group reported a reduction in neck pain while the U.S. group reported a reduction in shoulder pain. The Polish group reported an increase in neck, shoulder and forearm pain at follow-up compared to after intervention. The Polish group recorded higher flexion of the upper arm at follow-up parallel with an increase of pain in the upper part of the body. Visual discomfort showed variable results in the 3 countries.     

Relationship between musculoskeletal disorders and anthropometric indices among bus drivers in Zahedan city

Introduction. Most work-related musculoskeletal disorders (MSDs) are associated with improper postures and poorly designed workstations. This study is an attempt to examine the prevalence and severity of MSDs as well as anthropometric dimensions among city bus drivers. Methodology. This cross-sectional study was carried out on 60 male bus drivers. A body discomfort chart was used to evaluate MSDs. Spearman correlation was employed to examine the relationship between body size and the severity of discomfort. Results. Data analysis showed that discomfort reported in the lower back (33.3%), upper back (18.3%) and knee (15%) was severe and there was a direct and significant correlation between the body mass index and the severity of discomfort in the shoulder, arm and hip (p?p?Conclusion. The results of the study can be used to address ergonomic risk factors and reduce their associated disorders. The findings of the study can be used in training programs to educate drivers how to decrease the risk associated with work-related MSDs by adopting appropriate behavior strategies.     

An Attempt at Preventing Asthenopia Among VDT Workers

We report the results of 3 surveys of visual display terminal (VDT) users who took a minibreak during which they viewed a stereoscopic image of a repeating parallel pattern showing planets. The single image stereogram method employed is called Stretch Eye^TM, and we evaluated the effects of Stretch Eye^TM on asthenopia. An accommodative relaxation of about 1 D was observed in participants while they were gazing at the image. The employees of 2 information technology companies were evaluated according to a visual analogue scale (VAS) for subjective symptoms of asthenopia and eyesight. The results showed that Stretch Eye^TM was effective in easing visual fatigue due to VDT work and it improved eyesight under working conditions.     

Self-Rated Physical Loads of Work Tasks Among Firefighters

Objectives. The present study sought to identify firefighters’ rated physical demands for the most frequently occurring work tasks and to determine if the ratings differed between full-time and part-time firefighters to help create a basis for the development of physical employment tests for firefighters. Methods. An extensive questionnaire was completed by 125 and 68 firefighters in 2000 and 2010, respectively. The data were analysed with the Mann-Whitney U test and binominal test and ranked on the basis of the responses in each category. Results. Significant differences were seen between the full- and part-time firefighters. The work tasks rated as the most physically strenuous in terms of aerobic fitness, muscle strength, work posture and body control by most respondents were smoke diving upstairs (carrying a hose), victim rescue in different ways, carrying a stretcher over terrain and pulling a hose. Conclusions. Physically strenuous work tasks should be included in the end-point performance variables used to select physical performance tests for firefighters. The part-time firefighters with no experience in several of the work tasks suggests that work-related exercises are important if both groups of firefighters are expected to do similar work.