Evaluation of ergonomic intervention strategies for drywall installation

Construction workers performing drywall installation are exposed to a variety of ergonomic hazards, including heavy material handling, repetitive motions and awkward postures. The rates of musculoskeletal injuries and disorders among drywall installers are very high, especially at the low back and shoulder. Injury prevention strategies potentially exist to reduce the ergonomic hazards and promote drywall installers' health and safety. Despite the existence of these strategies, little is known about their efficacy and effectiveness in the construction workplace. The present research investigated the following ergonomic interventions: lifting assistance, two-person team work, alternative work-rest schedule alone and combinations with the other two. Utilizing the integrated methodologies of PATH (Posture, Activity, Tools, and Handling, a work-sampling based approach), Monte-Carlo simulation, biomechanical modeling, and a one-compartment challenge-recovery model, this study examined the intermediate outcomes including the required muscle contraction forces, joint resultant forces, prevalences of muscle fatigue, and muscle consecutive fatigue periods to demonstrate the biomechanical advantages of different intervention strategies. Among those proposed ergonomic interventions, the combination of lifting assistance and alternative work-rest schedule proved to be the relatively most efficacious in reducing both the physical loads and muscle fatigue on the low back and shoulder for drywall installers.