Work characteristics, musculoskeletal disorders, and the mediating role of psychological strain: a study of call center employees.

The demands of the modern office are thought to contribute to the development of musculoskeletal disorders. For upper body and lower back disorders, these effects are hypothesized to be mediated by psychological strain. A study of 936 employees from 22 call centers supports this hypothesis. Using logistic regression and structural equation modeling, the authors found that the relationship of workload to upper body and lower back musculoskeletal disorders was largely accounted for by job-related strain. This mediating effect was less evident for arm disorders. Contrary to expectation, job autonomy had neither a direct nor a moderating effect on any musculoskeletal disorder.

Work characteristics, learning-related outcomes, and strain: a test of competing direct effects, mediated, and moderated models.

Direct effect, mediated, and moderated models of the relationship among work characteristics (job control, job demands), learning-related outcomes (skill utilization, self-efficacy), and strain (anxiety, depression) were compared. Three independent samples of call center employees were used, 2 cross-sectional (Ns = 427 and 203) and 1 longitudinal (N = 144). Initial analysis of the cross-sectional samples using structural equation modeling revealed that mediated models provided the best fit to the data. Skill utilization mediated the effect of control on depression, and depression partially mediated the effect of control on skill utilization. Longitudinal hierarchical regression analysis confirmed these findings. Results indicate that, in this occupational context, learning reduces strain, strain inhibits learning, and job control is an important precursor of both these relationships.