On-Site Evaluation of Back-Support Exoskeleton Effectiveness in Construction: A Multiple Case Study of Physical Performance, Ergonomic Comfort, and User Acceptance among Masonry Workers

Work-related musculoskeletal disorders (WMSD) remain a major concern in the construction industry, largely due to labor-intensive tasks characterized by repetitive lifting and awkward postures. Although various ergonomic interventions exist, high injury rates persist, underscoring a need for innovative solutions. Exoskeletons have emerged as a promising technology to reduce physical strain, yet empirical evidence of their effectiveness in real construction environments remains limited. This study employs an embedded multiple case study approach conducted over a period of four months across five construction sites with 15 masons to investigate the efficacy of two distinct back-support exoskeleton (BSE) designs. Through structured interviews, baseline and post exoskeleton data were collected over three days per mason, focusing on perceived exertion, fatigue, ergonomic comfort, and user acceptance. Results indicated substantial reduction in physical strain, including a 26.74% decrease in perceived exertion and a 42.11% reduction in fatigue. However, 93% of masons reported movement restrictions and all experienced strap-related discomfort, leading to a 57.41% decline in willingness to continue use despite proven physical benefits. This research contributes to the body of knowledge by demonstrating that exoskeleton implementation success in construction depends equally on biomechanical effectiveness and practical usability, revealing a critical gap between laboratory-proven benefits and field adoption that must be addressed through improved comfort design, realistic expectation management, and task-specific deployment strategies. These findings provide evidence-based guidance for manufacturers prioritizing design improvements and construction companies developing implementation strategies for exoskeleton technology in real work environments.