Documents Karasek, Robert 4 results

"There is increasing interest in distinguishing the effects of physical and psychosocial workplace stressors on the aetiology of work-related musculoskeletal disorders (MSD). Modest associations have been found between psychosocial stressors and MSD, such as intensive load, monotonous work and low job control. Interpretation of these results has been limited by likely covariation between physical and psychosocial stressors. This investigation examined exposure covariation among blue- and white-collar workers employed in a mass production manufacturing environment (N = 410). Physical stressors were assessed from questionnaire and accelerometry. Psychosocial stressors were assessed from questionnaire. Pearson and Spearman correlation coefficients were computed. An exploratory factor analysis procedure identified possible common factors linking specific physical and psychosocial stressors. Moderate to high correlations between some physical and psychosocial stressors showed evidence of covariation both across and within groups. Covariation was strongest among blue-collar production and low-status office workers. Factor analysis results showed considerable shared variance between some physical and psychosocial stressors, such as repetition and job control, suggesting that these disparate stressors manifest from common work organization factors that govern the structure of work. While recognizing the conceptual differences between physical and psychosocial stressors, these results call attention to the strong empirical relationships that can exist between some stressors in the workplace setting. To guard against ambiguous study findings that can occur when exposures are mixed, it is critical that future epidemiologic studies include information about the degree of association between task-level stressors. Future research on work organization determinants of task-level stressors, and their coincident occurrence in jobs with greater specialization, may provide promising new insights into the nature of risk for MSD and effective prevention strategies. "

"Background: Little is known about the role of low physical activity at work (sedentary work or low physical job demand) in the increasing prevalence of obesity of US workers.
Methods: This cross-sectional and secondary data analysis included 1,001 male and 1,018 female workers (age range: 32–69) from the National Survey of Midlife Development in the United States (MIDUS) II study (2004–2006). Sedentary work and physical job demand were measured by questionnaire items. Total obesity (based on body mass index) and central obesity (based on waist circumference) were defined using WHO criteria.
Results: After controlling for covariates (socio-demographic, psychosocial working conditions, health status, and health behaviors), sedentary work, low physical job demand, or their combination increased the risk for total and central obesity in male workers, particularly when they worked longer than 40?hr per week. Sedentary work marginally increased the risk for total and central obesity in female workers.
Conclusions: Low physical activity at work is a significant risk factor for total and central obesity in middle-aged US male workers."