Applying implementation science to evaluate participatory ergonomics program for continuous improvement: A case study in the construction industry

While participatory ergonomics (PE) presents numerous benefits, its empirical effectiveness remains elusive due to the lack of transparency in implementation contexts and processes. This hinders our ability to discern the reasons behind a program's success or failure and to determine optimization and adaptation strategies. To unravel this "black box," we present a case study using implementation science to evaluate a PE program and illuminate the mechanisms linking process to outcome. The study examines a 4.5-year PE program at a construction company, targeting musculoskeletal disorders (MSDs) from material-cart handling. Using the RE-AIM framework and Implementation Causal Pathway Model, we evaluated implementation process and catalogued contextual factors through worker surveys (n = 106), safety document review (27 training sessions and 7 construction projects), and key informant observations. We assessed the program's impact using a 42-worker survey and an analysis of 8-year injury data, and determined the return-on-investment (ROI) by monetizing the collected data. The program achieved significant impact: Workers' ergonomic knowledge improved from 73% in baseline to 86% in follow-up; 97% of workers reported at least one positive change in their crews; and no cart handling injuries occurred after the first program change, resulting in a ROI rate of 1.99. Implementation process evaluation revealed that seamless integration, tailored intervention, and ongoing adjustments contributed to the success. Five organizational factors necessary for the effective functioning of these three strategies were identified, along with three moderators that amplified their influence. Finally, this case study demonstrates that implementation science offers a coherent structure for evaluating PE programs, uncovering mechanisms of change, and informing future improvements and adaptations. Our research facilitates knowledge transfer from implementation science to ergonomics, eventually leading to more cost-effective PE programs that are faithfully implemented across various industrial settings to prevent MSDs.