Psychophysiological stress reactions,trapezius muscle activity,and neck and shoulder pain among female cashiers before and after introduction of job rotation

The aim of this study was to evaluate the effects of the introduction of a job rotation model on supermarket cashiers, with respect to psychophysiological stress reactions, muscle activity of the trapezius muscle (which covers the upper back, the neck and the shoulder), and musculoskeletal symptoms in the neck and shoulders. Thirty-one female cashiers were investigated before and after job rotation was introduced. Before the reorganization the participants were only performing cash register work at the checkout counters. After the reorganization they shifted between cash register work and work in different departments in the supermarket. At follow-up the participants, all right-handed, had a significantly lower diastolic blood pressure, and surface electromyography (EMG) showed a significantly decreased muscle activity in the trapezius muscle on the left side. Musculoskeletal symptoms of the neck and shoulders were only partly changed, and there was no change in prevalence of musculoskeletal pain, which was around 70%. From questionnaires, but not from self-ratings during work, it was found that the introduction of job rotation had been experienced as positive in several regards, although the perceptions of stress and hurry were the same at follow-up.     

Psychophysiological stress reactions, trapezius muscle activity, and neck and shoulder pain among female cashiers before and after introduction of job rotation

The aim of this study was to evaluate the effects of the introduction of a job rotation model on supermarket cashiers, with respect to psychophysiological stress reactions, muscle activity of the trapezius muscle (which covers the upper back, the neck and the shoulder), and musculoskeletal symptoms in the neck and shoulders. Thirty-one female cashiers were investigated before and after job rotation was introduced. Before the reorganization the participants were only performing cash register work at the checkout counters. After the reorganization they shifted between cash register work and work in different departments in the supermarket. At follow-up the participants, all right-handed, had a significantly lower diastolic blood pressure, and surface electromyography (EMG) showed a significantly decreased muscle activity in the trapezius muscle on the left side. Musculoskeletal symptoms of the neck and shoulders were only partly changed, and there was no change in prevalence of musculoskeletal pain, which was around 70%. From questionnaires, but not from self-ratings during work, it was found that the introduction of job rotation had been experienced as positive in several regards, although the perceptions of stress and hurry were the same at follow-up.     

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.     

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.     

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.     

Media Exposure to Terrorism and Perception of Immigrants as a Threat: The Role of Emotional Intelligence and Psychophysiological Self-Regulation

To better understand how media exposure to terrorism-related images can lead to perceiving immigrants as more threatening, in the present study we manipulated participants’ exposure to media coverage of terrorist attacks and investigated how this may influence people's perception of Arab immigrants. Considering the important role of regulatory abilities when facing stressful events like terrorist attacks, we measured individual differences in both trait emotional intelligence and resting heart rate variability (HRV). Results showed that participants perceived Arab immigrants as more threatening in the media exposure condition than in the control condition. Importantly, there were moderating effects of both trait emotional intelligence and HRV. People with lower trait emotional intelligence or lower HRV at rest felt more threatened in the media exposure condition compared to the control condition, whereas this effect was not observed among participants with higher trait emotional intelligence or higher resting HRV. The present study highlights some of the complexities related to how media exposure to terrorism-related images influences people's reactions to, and evaluations of, an outgroup that is related to the perpetrators of the attacks.     

Psychosocial factors and safety behaviour as predictors of accidental work injuries in farming

Abstract

Farming is one of the most hazardous occupations in terms of the incidence and seriousness of accidental injuries. Research with other occupational groups has drawn attention to the role of psychosocial factors and stress. Such research needs to be extended to agriculture. Since stress may be a problem faced by farmers, there is a particular need to investigate the associations between farm accidents and work stressors and stress reactions. Using multivariate logistic regression analyses, this study aimed to uncover the best psychosocial predictors of injury, while controlling for exposure-related confounders. From a randomly selected sample of 794 farms, 10% of all farms in Ringkoebing County, Denmark, 393 farmers completed completed weekly accident registration over 12 months. The study sample consisted of 310 farmers who also completed questionnaires on psychosocial factors. Results indicated that farm stressors (including perceived economic problems), stress symptoms, and safety behaviour were predictors of occupational farm accidents. Higher levels of stressors and stress symptoms and poor safety behaviour were all associated with an elevated risk of injury. In the case of stress symptoms, the relation with accidents occurred via an interaction with safety behaviour. The combination of high levels of stress symptoms and poor safety behaviour was associated with a particularly high accident risk.     

Investigating effort–reward imbalance and work–family conflict in relation to morningness–eveningness and shift work

Abstract

An increasingly older workforce and a growing emphasis on jobs involving interaction with computers have resulted in a need to more carefully examine the relationship between ageing and computer-based work. In this study, a sample of 394 subjects ranging in age from 20-75 years performed a computer task across a 3-day period. Three different types of computer-based jobs (data entry, information retrieval, and accounts balancing) performed at three large US companies were simulated. Age differences in the subjective experience of stress, workload, and bodily discomfort were evaluated. The results indicated that age effects for these measures varied according to task. The older subjects perceived greater workload for the more mentally challenging problem-solving oriented accounts balancing task (Which involved a graphical user interface) than the younger participants, even with increased exposure to the task. However, the older subjects generally experienced less stress than the younger subjects on an information retrieval task that involved a more socially interactive telephone component. A positive relationship between the frustration component of workload and the measure of stress was also found, suggesting an important link between the constructs of stress and workload. Overall, the outcomes of this study provide important insights into design interventions intended to accommodate older as well as younger persons in the workforce.     

The Danish psychosocial work environment and symptoms of stress: The main,mediating and moderating role of sense of coherence

The aim of this cross-sectional study was to explore the main, mediating and moderating role of sense of coherence (SOC) on stress symptoms and on the association between perceived psychosocial work environment and stress symptoms. The sample includes 2053 Danish employees from 52 workplaces. Hierarchical regression models were applied for each measure of stress. The results strongly supported the presence of a main effect for SOC. People with high levels of SOC experienced fewer stress symptoms. A mediating effect of SOC was also supported. Thus, SOC in part explained the association between work environment and stress symptoms. In addition, some support for a moderating effect of SOC was found, suggesting that people with higher SOC coped more efficiently with work environmental strain that people with lower SOC. Taken together the regression models explained 11–32% of the variance in stress symptoms. The results suggest that measures of individual factors such as SOC should be included in analyses of the effects of work environmental factors on stress and well-being.     

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.     

Stress,health and the working environment of Swedish prison staff

Abstract

A random stratified sample of just over 2000 was drawn from staff working in 67 different prisons in Sweden. Questionnaires on working conditions and symptoms of ill health were administered and subjects were given health examinations. Morning plasma Cortisol and gamma glutamyltransferase (g GT) levels were measured and factual information on the prisons was collected for use in the analyses.

There were differences between prisons in terms of both objective and self-reported working conditions which appeared to affect health status, physiological state and sick leave rate. Cardiovascular and hypertensive conditions were found more often among prison staff than among a large reference group made up of many different occupations. Sick leave rates among prison staff, especially those over 45 years old, were very high compared with this reference group. The situation appeared particularly difficult in prisons with a high proportion of drug abusing inmates.

The data allowed the identification of several factors which might counteract the effects of stress at work: a proactive management style, goal consensus among staff, a high degree of decision latitude, satisfaction with work performance and a supportive psychosocial climate.     

Shiftwork tolerance and circadian rhythms in oral temperature and heart rate

Abstract

The study aimed at establishing differences in the circadian rhythm parameters of oral temperature and heart rate between three groups of workers matched by age: tolerant shiftworkers with good sleep quality and few psychosomatic and digestive complaints, intolerant shiftworkers with poor sleep quality and more psychosomatic and digestive complaints, and workers who had never worked in shifts. The study was performed at an oil refinery recreation centre where the subjects were isolated for three days. During that period they lived under constant conditions, i.e. their activities, timing and content of meals, ambient temperature and light were controlled. Hourly measurements of oral temperature and heart rate were performed over a 24-h period. The parameters of the physiological rhythms were estimated by means of the COSINA method. Generally, the differences between the groups were low and not statistically significant. The authors could find no difference in the amplitude and phase position between the tolerant shiftworkers unlike other authors. The difference between these results and those of others is likely to be due to the fact that earlier studies were performed in field conditions where many factors that could have masked the results were not controlled for.     

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.     

Healthy lower backs in the construction industry in Sweden

This corss-sectional study exmaines the relationship between healthy lower and psychosocial and physical factors in a random sample of 1773 male construction workers. Infoamtion on lower back status, lifestyle habits, stress, psychosomatic and psychological symptoms, psychosocizal demands and resoruces and physical workload were collected by means of a postal questionnaire. Measures of psycholocial and physical factors were based on factor analysis of the data. The criterion variable 'healthy lower back' (HLB)—no lifetime history of low back pain—proved to be valid compared with an interview and a physical examination. A total of 216 workers (12%) reported HLB. The prevalance rate decreased significantly with increasing age. The prevalence rate of HLB was 6% among workers reporting high stress levels. It was postively influenced when there was a balance between demands and resoruces. A low level of physical workload also increased the prevalence rate of HLB. When age, lifestyle and physical factors were kept constant in a multivariate analysis high scores on the discretions index and low scores on eh psychosomatic, psychological and stress indices cosntributed significantly to an increase prevalence rate of HLB.     

Perceived exertion under conditions of sustained work and sleep loss

Abstract

The rated perceived exertion (RPE) for treadmill walking carrying a 22 kg pack was measured in two studies with heart rate, workload and psychological measures. Study 1 used an initial treadmill speed and grade producing 40% of maximal oxygen consumption. Exercise subjects walked 1/2-h, then did other tasks for 20-h for 16 sessions on two 20 h long days. Group I had a 4 h nap, while Group 2 had 4 h of rest between workdays. Subjects maintained the 40% workload throughout the two days with a 3 h nap between days, one group starting exercise at midnight and one at noon.

A steady increase in RPE over the sessions each day was found in each study. There were no differences in RPE between the Nap and Rest groups in Study 1 or between the midnight and noon groups in Study 2. RPE was higher on Day 2 in each study. RPE correlated significantly with heart rate, distance walked or elevation at most time periods on the first workday in Study 1, but not Study 2. RPE was positively correlated with fatigue, symptoms, sleepiness and negative mood, and negatively correlated with vigor at most of the time periods day 1 in Study 2; with similar significant correlations at only one time period on day 1, Study 1. RPE was lower the first session Day 2 as compared to the last session Day 1 in both studies. This pre-post break recovery did not differ between groups in either study.     

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.     

Work-related psychosocial,physical and individual factors associated with musculoskeletal symptoms in computer users

The aim of this study was to study associations between psychosocial, physical and individual factors, and musculoskeletal symptoms in the neck, shoulder and hand/wrist regions of computer users. Questionnaires were distributed to 5033 employees in 11 Danish companies; these employees all used computers for at least some of their work time. The response rate was 69% ( n = 3475). The analyses were based on employees working 32-41 h/week ( n = 2579). Symptomatic respondents reported symptoms for at least 8 days within the previous year. Multiple logistic regression analyses were used. Gender (female), age and duration of employment in the same job were associated with an increased prevalence of symptoms. High quantitative job demands and low possibilities for development at work were predictors of neck and hand/wrist symptoms. A high degree of repetitiveness and disturbing reflections on the computer screen were associated with symptoms in all three body regions. Repetitive movements were defined as the same finger, hand or arm movements performed many times per minute for at least 75% of their work time. Repetitiveness was the only factor that could partly explain associations between symptoms and duration of computer use, i.e. respondents who used the computer almost all the time at work reported more repetitive movements than those who used it less. Thus, long hours of computer use may be associated with musculoskeletal symptoms, due to physical factors such as repetitive movements, whereas psychosocial factors appeared to be associated with the symptoms independently of the duration of computer use.     

Heart rate and blood pressure in male police officers and clerical workers on workdays and non-workdays

Abstract

Male police officers from a city police station in Tasmania (n = 20) and a matched group of clerical workers (n = 20) monitored their heart rate, blood pressure and self-reported levels of stress and arousal over a two-week period. Measurements on workdays during which stressful events occurred were compared to non-event workdays and non-workdays. Two group differences were demonstrated, with the clerical workers reporting higher levels of stress, and the police officers reporting higher levels of arousal. Support was evident for the distinction between workdays and non-workdays, and support was demonstrated for differences between different types of workdays. Evidence suggested that restricting the time frame of such research may lead to results that are inaccurate or inconsistent because workdays differ in content.     

The role of stress and social support in Sick Building Syndrome

Sick Building Syndrome (SBS) involves seemingly healthy individuals experiencing long-lasting symptoms of physical distress in their work settings and is estimated to exist in 20 to 30% of all work settings in the USA. We examined differences in stress, social support and both physical and psychological symptoms reported by hospital personnel working in known SBS sites in Halifax, Nova Scotia (n = 297) with control employees working in relatively SBS-free settings (n = 228). We found that employees reporting that their health had been affected by the building in which they worked and those complaining of poor air quality were more likely to be found in SBS locations. In addition, those people with higher levels of organizational support and marginally higher levels of union support were also more likely to be found in SBS locations. Further analyses revealed that employees with higher role overload and greater family support, but lower levels of organizational support were more likely to report that their own health had been adversely affected by their place of work. Perceptions of poor air quality were predicted by higher levels of role conflict, role overload, and organizational stress and lower levels of organizational support. These results suggest that SBS may not be solely dependent on environmental factors.