The influence of psychological stressors on myoelectrical signal activity in the shoulder region during a data entry task

Psychological stress is suspected to play a key role in the development of work-related musculoskeletal disorders (WMSDs), and work pace may be a primary contributor. The purpose of this study was to observe how psychological stress affects muscle activity recorded from key muscles used to support the shoulder (the trapezius and levator scapulae muscles) during keying tasks. We hypothesized that muscle activity [amplitude of the myoelectric signal (MES)] would increase and the number of periodic rests in muscle activity ('EMG gaps') would decrease when computer work was performed at an increased pace, and with distractions in the environment. Ten healthy volunteers performed three typing tasks (N = no stress; I = stress induced by a work pace reward; IS = stress induced by a work pace reward plus irritation/distraction). Both muscles showed significant increases ( p < .05) in MES amplitude when comparing IS to the N and I conditions, whereas N and I were not different. There was significant reduction in the number of gaps observed during the I and IS conditions (essentially no gaps were observed) as compared to the N condition. Interestingly, MES amplitude measures were capable of preferentially detecting changes in activation due to the distraction stress, whereas the number of EMG gaps preferentially detected the stress of the increase in work pace. The effect of these stressors on heart rate and productivity are also discussed.     

Stress, physical activity and coronary heart disease

Recent years have witnessed an increasing popularity of corporate fitness programmes. Regular physical activity and, in particular, high aerobic fitness are associated with a lower risk of coronary heart disease. Apart from its beneficial effects on resting levels of blood pressure and cholesterol, fitness is believed to reduce the impact of psychological stress. This hypothesis has been put to the test in 33 studies examining the physiological stress response of groups selected to differ in their fitness level. Although some evidence was found for a reduced response to stress in high fit subjects, the effects were not very strong. During 54 confrontations with a stressful task, significantly lower heart rate reactions in high fit subjects were seen in only nine tasks (17%). With nine out of 36 stressors (28%), fit subjects showed a lower diastolic blood pressure response. However, in combination with a frequently found reduction in basal levels, the high fit showed a consistently favourable cardiovascular profile under stress. This adaptation may reflect the benefits of regular exercise over a more sedentary lifestyle, but a combined influence of genetic make-up on cardiovascular reactivity and fitness cannot be ruled out.     

Psychological stress and muscle activity during data entry at visual display units

Abstract

The aim of this study was to evaluate whether psychological stress causes increased muscle activity, especially static muscle activity, in the trapezius muscles of the neck and shoulder. A pilot and a main study were carried out with 10 males and 20 females, respectively. The subjects performed a VDU data entry task under psychologically stressful and non-stressful conditions. Stress reactions were measured by different methods: heart rate and heart rate variability, hormonal excretion, and subjective ratings of mood and body symptoms. The stress condition caused an increase in heart rate. The low-frequency variability increased and the high-frequency variability decreased. Ratings of motivation and relaxation decreased, and subjects felt more activated. Pain and discomfort from the stomach increased. Adrenaline and noradrenaline in urine were unaffected. The majority of the subjects showed moderately increased static and median EMG levels during the stress condition. The interindividual variation in muscular reactions was large. Statistically significant increases were obtained for the myoelectric activity of the left (resting) trapezius muscle when pooling the two groups. It appears that the increase in muscle activity due to this type of mental stress is small, and factors other than ‘attention-related’ load may be more important. The results indicate that some individuals may be more prone to general muscle tension, making them more likely to develop symptoms and musculoskeletal pain.     

Effects of experimentally induced mental and physical stress on motor unit recruitment in the trapezius muscle

Mental stress may induce muscle tension and it is thought to contribute to the development of musculoskeletal disorders. Prolonged activity of a muscle's motor units (the smallest functional units) having low activation thresholds, may cause metabolic disturbances, degenerative processes and pain. The present experiment was aimed at investigating if the same motor units are activated by mental stress as by physical demands. Seventeen participants were exposed to mental stress tests (mental arithmetic, Stroop color word) and physical demands (standardized reference contraction, force ramp contraction) in the laboratory. In addition, they were exposed to the cold pressor test. Bipolar intramuscular electromyographic (EMG) activity was measured in the trapezius muscle, which covers the upper part of the back, the neck and the shoulder, and an automatic classification programme was used to separate the contributions of the individual motor units in the compex EMG signal. Overall muscle activity was measured by bipolar surface EMG and heart rate was recorded as an indicator of stress. The mental stress induced significant increases in muscle activity ( p < .05) and in heart rate ( p < .05). In 12 out of 14 participants, one or more motor units were found to be active in mentally as well as in physically induced muscle contraction. The results indicate that mentally induced stress may contribute to keeping low threshold motor units active, even in the absence of physical demands. Considering the health risks of prolonged motor unit activity, it was concluded that lack of mental rest is an important risk factor for the development of muscular pain.     

Job stress, satisfaction and mental health of factory workers in Bangladesh

The present study examined the relationship between job stress, job satisfaction and mental health, and attempted to assess the effects of job stress on different parameters of satisfaction and mental health in the context of two groups of Bangladeshi factory workers. There were 26 subjects in a 'high stress' group and 33 in a 'low stress' group. Individual data were collected by using the Stress and Arousal Checklist, the Job Satisfaction Scale, the General Health Questionnaire, absenteeism by sick leave, a self-esteem at work scale and heart rate monitor. Chi-square and t-tests were applied in the analyses of these data by group. The results, quite expectedly, showed that a greater number of high stress subjects were dissatisfied and had poorer mental health than low stress subjects. The results also showed that low stress subjects were significantly more satisfied and possessed better mental health than the high stress subjects. It would appear that the experience of stress plays an important role in determining the quality of working life of Bangladeshi factory workers having similar consequences in terms of health and well-being to those observed in developed countries. The dynamics of absenteeism in Bangladesh are discussed.     

A community study of dual-role stress and coping in working mothers

This paper describes a pilot study in a community in North London of dual-role stress and coping in three groups of working mothers with dependent children at home. One group was married and enjoying comparatively high income; another was 'single' and also with comparatively high income; the third group was 'single' with comparatively low income. There were 15 women in each group. The study was by interview and questionnaire. Evidence of dual-role stress was found in the study, and the results are consistent with conclusions drawn from the literature. However, many women appeared to obtain important benefits from going to work, and there was considerable evidence of good coping, especially in terms of drawing on the informal support of other women. Both the quality of the job and quality of domestic support were important for the working mother's stress management. The relative poverty of organized child-care in Britain was reflected in the child-care problem reported by most of these women and the 'single' women in particular. Low income 'single' women reported greatest levels of stress and strain, financial and child-care stress, and work stress.     

MODELING TIME-COST TRADE-OFFS IN CPM NETWORKS

A new type of PERT/CPM methodology is introduced whereby the individual activities within a project management network are endowed with resistive and capacitive elements. This methodology will enable us to mathematically define a completion time for the various activities and to relate the completion time to relevant cost in the completion of a particular task. It will also allow us to define the work done, and the rate at which work is being done, in an activity as a function of the applied effort and resource outlay. As a consequence, both the resource expenditure and the work done can be tracked within a network as a function of time.     

Individual strategies for coping with stress at work: A review

This paper discusses some of the conceptual and methodological issues involved in the study of coping. It focuses on individual coping with work and work-related problems, and adopts a transactional framework for the definition of the key concepts of stress, appraisal and coping. It identifies and reviews 17 recent papers which are representative of the coping literature, as defined by the scope of the paper. What it draws out of this review largely concerns issues of measurement, and four particular issues are flagged as important for future research. It concludes that there is a need for more and more adequate studies, particularly in relation to the classification and modelling of coping, and that the adequacy of those future studies should be partly judged in terms of how well they deal with the issues raised here.     

The effects of fitness training on the physiological stress response

The favourable psychological and physiological profile found in fit sportsmen does not necessarily follow from their exercise behaviour. Alternatively it may depend on endowment and/or self-selection. In that case, participation in regular exercise may not always result in a reduction of susceptibility to stress. The present article reviews several well-controlled laboratory studies that have directly examined the effect of fitness training programmes on the physiological responses to a set of standardized stressors. It was generally expected that fitness training would enhance psychological stress resistance and thus mitigate the physiological response to stress. The results of most studies belie these expectations. Intensive training programmes of up to 8 months do not change stress reactivity, even if initially low fit and high stress-reactive subjects are used. The failure to find a training effect on the intensity of the stress reactions in laboratory studies does not rule out possible psychosocial effects of regular exercise on the frequency and duration of the stress reactions in real-life situations. Furthermore, although the dynamics of the physiological response to stress are not changed, there is a clear downward shift in the overall level of heart rate and blood pressure in stressful situations. Several possible mechanisms are suggested by which these training effects may help us to deal with work stress without suffering health problems.     

The moderating role of social support in Karasek's job strain model

The potential stressfulness of an event may depend on how it is appraised by the individual, although up to now there have been no longitudinal studies on the relationship between lay beliefs concerning work stress and perceived strain. This longitudinal study examines how lay theories of work stress at baseline were related to perceived mental strain at follow up. The present paper builds on an earlier study (Furnham, ), using a longitudinal design and a much larger population of the British workforce (N=2270). Lay beliefs were assessed by a scale consisting of 36 items. Factor analysis gave a solution with five factors on perceived causes and four factors of perceived alleviation of work stress. Linear multiple regression analysis revealed significant relations between lay beliefs of work stress at baseline and perceived mental strain as well as job stress 14 months later. The effect sizes were small but of a similar magnitude to those that have been found, for example, in occupational stress-reducing interventions. A problem with the factor analytic approach was the discrepancies between the factor solutions and the relative importance of the perceived causes of work stress. The results from the study suggest that subjective beliefs about work stress merits further analysis as potentially mediating between ‘objective’ working conditions and stress outcomes.     

Are lay theories of work stress related to distress? A longitudinal study in the British workforce

The potential stressfulness of an event may depend on how it is appraised by the individual, although up to now there have been no longitudinal studies on the relationship between lay beliefs concerning work stress and perceived strain. This longitudinal study examines how lay theories of work stress at baseline were related to perceived mental strain at follow up. The present paper builds on an earlier study (Furnham, 1997), using a longitudinal design and a much larger population of the British workforce (N=2270). Lay beliefs were assessed by a scale consisting of 36 items. Factor analysis gave a solution with five factors on perceived causes and four factors of perceived alleviation of work stress. Linear multiple regression analysis revealed significant relations between lay beliefs of work stress at baseline and perceived mental strain as well as job stress 14 months later. The effect sizes were small but of a similar magnitude to those that have been found, for example, in occupational stress-reducing interventions. A problem with the factor analytic approach was the discrepancies between the factor solutions and the relative importance of the perceived causes of work stress. The results from the study suggest that subjective beliefs about work stress merits further analysis as potentially mediating between 'objective' working conditions and stress outcomes.     

Perceptions of work stress in Australian firefighters

This study surveyed 747 firefighters on their perceptions of work stress. The current emphasis in the fire brigades is on the management of traumatic or critical incident stress, but other work stressors may also be important. The firefighters rated their jobs as more stressful than other occupations, and psychological work stress as highest among a set of potential sources and types of stress. Although many factors were mentioned, the most frequently indicated stressors were associated with exposure to traumatic incidents such as major accidents or the suffering of others. Those who had previous experience with stress were more likely to rate current and future risk of stress as higher. Knowledge of existing organizational approaches to stress management was limited. The firefighters rated individual and informal sessions for dealing with stress as potentially more useful than the formal debriefing sessions now common in many emergency organizatins. Those who had previous experience with stress, however, were more likely to favour a formal organizational approach.     

Perceptions of work stress in Australian firefighters

Abstract

This study surveyed 747 firefighters on their perceptions of work stress. The current emphasis in the fire brigades is on the management of traumatic or critical incident stress, but other work stressors may also be important. The firefighters rated their jobs as more stressful than other occupations, and psychological work stress as highest among a set of potential sources and types of stress. Although many factors were mentioned, the most frequently indicated stressors were associated with exposure to traumatic incidents such as major accidents or the suffering of others. Those who had previous experience with stress were more likely to rate current and future risk of stress as higher. Knowledge of existing organizational approaches to stress management was limited. The firefighters rated individual and informal sessions for dealing with stress as potentially more useful than the formal debriefing sessions now common in many emergency organizatins. Those who had previous experience with stress, however, were more likely to favour a formal organizational approach.     

Research into work stress in Italy: A review

This paper reviews the development of stress research in Italy from the late 1960s onwards. It focuses on 1975 as the year when the first real studies on work stress were published, and interest was kindled in the psychological factors which affect physical health and in the physiological correlates of work stress. Much important work in these aspects of occupational health was started at this time at the Clinic of Work in Milan and at the University of Perugia. By the 1980s, Italian psychologists were also showing considerable interest in work stress, and the more psychological literature had begun to exceed that of a medical and physiological orientation. Despite this progress, stress research in Italy is still in its infancy, and the recognition of stress as an issue for management and trade unions is weak.     

The impact of perceived organizational support on work meaningfulness,engagement, and perceived stress in France

This paper aims to show the strategic role of Perceived Organizational Support (POS) in developing positive work attitudes, thereby reducing stress in the workplace. We have conducted an empirical study to understand more about if and how work meaningfulness influence perceived stress and whether work engagement has a mediating effect between these two constructs. Based on the Job Demands-Resources (JD-R) model and Social Exchange Theory (SET), we hypothesize that POS has both direct and indirect relationships with these variables: meaningfulness, work engagement, and perceived stress. We tested these hypotheses through path analyses on a sample of 1111 employees in France. The results support our hypotheses on a) the negative association between meaningfulness and perceived stress, b) the mediating role of engagement, and c) the direct and indirect effects of POS. The strongest moderating effect of POS is observed on the relationship between meaningfulness and engagement. Our findings have theoretical implications by showing, for example, that POS enhances positive outcomes more than it diminishes negative ones. The results also have practical implications for managers and organizations as they reinforce the interplay of intrinsic motivators (meaningfulness) as an individual process as well as extrinsic motivators (POS) in the realm of an organization's responsibility and interest in strengthening employee engagement and reducing stress at work.     

Relationships between bullying, psychosocial work environment and individual stress reactions

It is frequently assumed that a poor psychosocial working environment will create conditions that encourage bullying. However, few studies have examined this assumption while comparing work environment ratings of bullied and non-bullied employees who work in the same organization and/or department. The objectives of this study were therefore, first, to investigate relationships between bullying and other psychosocial work environment factors within a particular organizational setting and, second, to investigate if bullied employees reported higher levels of stress than non-bullied employees. A total of 186 blue-collar employees from a Danish manufacturing company participated in the study (response rate of 93%). Results showed significant differences in bullied and non-bullied employees' ratings of psychosocial factors such as job control, management style, role clarity, social climate, social contact and work centrality. In order to investigate assumptions that a poor psychosocial work environment creates conditions that encourage bullying, a number of analyses compared the company's manufacturing departments with either high, medium or low levels of bullying. Results showed significant departmental differences. Yet, when bullied employees were removed from the statistical analyses, with regard to the perceived psychosocial environment these same departments could be differentiated only on the basis of rated job demands and management style. The results therefore bring into question the assumption that a generally poor work environment contributes to bullying. None the less, they do suggest that management style may directly or indirectly have contributed to a higher level of bullying. Also, bullied employees reported significantly more symptoms of psychological stress and mental fatigue than non-bullied employees.     

Relationships between bullying,psychosocial work environment and individual stress reactions

It is frequently assumed that a poor psychosocial working environment will create conditions that encourage bullying. However, few studies have examined this assumption while comparing work environment ratings of bullied and non-bullied employees who work in the same organization and/or department. The objectives of this study were therefore, first, to investigate relationships between bullying and other psychosocial work environment factors within a particular organizational setting and, second, to investigate if bullied employees reported higher levels of stress than non-bullied employees. A total of 186 blue-collar employees from a Danish manufacturing company participated in the study (response rate of 93%). Results showed significant differences in bullied and non-bullied employees’ ratings of psychosocial factors such as job control, management style, role clarity, social climate, social contact and work centrality. In order to investigate assumptions that a poor psychosocial work environment creates conditions that encourage bullying, a number of analyses compared the company's manufacturing departments with either high, medium or low levels of bullying. Results showed significant departmental differences. Yet, when bullied employees were removed from the statistical analyses, with regard to the perceived psychosocial environment these same departments could be differentiated only on the basis of rated job demands and management style. The results therefore bring into question the assumption that a generally poor work environment contributes to bullying. None the less, they do suggest that management style may directly or indirectly have contributed to a higher level of bullying. Also, bullied employees reported significantly more symptoms of psychological stress and mental fatigue than non-bullied employees.     

Lay representations of workplace stress: What do people really mean when they say they are stressed?

An individual's beliefs in relation to stress are likely to affect their perceptions, and hence their work-related actions (such as absenteeism). In this paper, lay representations of work stress were investigated utilising semi-structured interviews with 45 individuals from a range of occupations. The meaning of occupational stress, its antecedents and outcomes, and ways by which it may be managed were examined. Dominant factors were established through the use of thematic content analysis. Similarities and differences were found between lay and professional discourses on work stress. Results indicate that lay representations of occupational stress are multi-faceted. Little consensus was found in how participants interpreted the concept: a diverse range of personal, environmental, and societal factors was highlighted. A different (and arguably more complex) range of definitions of job stress and the manner in which it impacts on individuals was revealed than has been reported in previous studies. The causes of stress at work were perceived as being predominantly organisational, but the impact of stress on the employee was more salient than organisational outcomes. Paradoxically, secondary and tertiary stress management techniques were thought to be more effective than interventions designed to prevent stress at work. Interviewees with line management responsibility were more likely to emphasise individual responsibility for managing stress, most others maintained that the individual and the organisation are equally responsible. The potential value of examining lay representations of job stress to the discipline of Occupational Health Psychology is discussed and suggestions for future research are made.     

Psychological and physiological stress responses during repetitive work at an assembly line

The association between psychological and physiological stress responses was examined in 20 male workers at an assembly line. Each worker was studied during a 2 h period on two consecutive days in their normal job and, in order to obtain physiological baseline values, during a corresponding paid 2 h period off the job on the third day. Self-reports of work demands, mood, etc., measurements of catecholamine and cortisol excretion and of systolic and diastolic blood pressure and heart rate were obtained at the end of each of the three 2 h periods. Work induced a significant elevation in almost all psychological and physiological measurements. Levels were consistently lower in workers reporting a 'good' workday compared to those reporting a 'normal' or a 'bad' day. Correlations between self-reports and physiological values showed that catecholamine and cortisol responses, respectively, tended to be associated selectively with different psychological conditions, catecholamine values being associated with feelings of time pressure and pressure by demands, cortisol values with irritation, tenseness and tiredness. The results show that perceived stress at an assembly line is consistently reflected in cardiovascular and neuroendocrine functions of the workers.     

Making sense of visual management through affordance theory

Visual management is much used within operations management practice, particularly in association with process improvement initiatives in diverse areas such as production and healthcare. The practitioner literature abounds with suggested best practice. However, there is little attempt to theorise about why the design and use of ‘visual’ devices for such process improvement works in practice. Within this paper we describe a novel theory of operation which highlights the role that material and visual artefacts proposed by visual management practitioners play within particular ways of organising work. We develop an innovative way of employing the theory of affordances to explain how first- and second-order affordances, situated around the visual devices at the heart of visual management, connect three domains of action, which we refer to as articulation, communication and coordination. Our analysis of three cases from healthcare, clothing manufacturing and software production help ground the theorisation discussed.