Introduction: Job rotation (JR) is one of the most practiced organizational interventions for prevention of musculoskeletal disorders (MSDs) despite prior reviews reporting “weak” or “inconsistent evidence” for a positive effect of JR on health. JR redistributed tasks to decrease repetitive and monotonous task exposure and increase variability for individual workers. However, many JR studies have only assessed change in exposure amplitude without consideration of variability. This is problematic as the average exposure across workers is expected to remain relatively unchanged when tasks are redistributed among workers (assuming tasks occur to the same extent), while the amount of variability a worker experiences is expected to change (if the JR tasks are sufficiently diverse). Consideration of variability has not either been a priority in previous reviews assessing the evidence for the effectiveness of JR. 

Methods: We systematically reviewed the evidence that JR increases within-worker physical exposure variability and, within the included studies, that JR positively impacts health. We searched three online databases for papers that had (i) studied actual work (not laboratory or simulation studies); (ii) compared different work organization strategies including a group with task rotation and one without; and (iii) assessed physical exposures using observation or technical measurement. We extracted data on mean exposure values (for comparison with previous reviews) and any measures of variability (within or between workers). Within the set of included studies we also extracted health outcomes related to the JR. Prospero registration number: CRD42023438200

Results: Seven studies met the inclusion criteria, of which only two considered within-worker variability. Most studies introduced new tasks as part of the JR, thus any changes could not be uniquely attributed to the JR but may have resulted from new task(s). No studies assessed if the JR tasks were sufficiently diverse to plausibly increase variability.  Results for the effect of JR on health were inconsistent across the six included studies that presented health outcome data. 

Discussion: As only seven studies were found that met the study criteria and only two of these reported metrics of variability, there was insufficient evidence available to assess the effectiveness of JR to increase variability. Further, several common methodological issues were identified including the introduction of new tasks and the lack of quantification of task diversity. These factors further limited the extent to which the efficacy of JR could be assessed. 

Conclusion: Insufficient evidence exists assessing the impact of JR in studies using observation or technical measurement to quantify changes in physical exposures in actual workers in real-life JR initiatives, particularly for metrics of variability. Consideration of variability is key to JR studies since the proposed effects of a JR on improved musculoskeletal health are expected occur through JR-related increases in variability. Suggestions will be offered to guide future JR study design and exposure metrics to evaluate JR effectiveness to foster evidence generation on the benefits of JR in the context of musculoskeletal health.