Abstract
Masonry is a highly physical occupation with a low retention rate in the workforce beyond 5 years. Predominantly, workers leave the workforce because of injuries. In particular, musculoskeletal disorders are depleting the construction workforce. Previous studies have contrasted the safety records of journeymen versus novices. However, no study to date has examined the combined effects of experience level on safety, productivity, and the balance between them. The purpose of this study is to fill this gap and to investigate the underlying reasons for these effects. Twenty-one masons distributed in four experience levels were recruited to build a 72-block six-course wall using standard concrete masonry units. Participants' body kinematics were tracked using inertial measurement units and video cameras simultaneously. Biomechanical analysis was carried out to examine the loads experienced by major body joints during bricklaying. Results indicate that journeymen with more than 5 years of experience as well as novice masons work in ergonomically safer ways than apprentices with 1 and 3 years of experience. It was found that apprentices gain proficiency and increase productivity at the cost of higher risk of musculoskeletal injury. The results indicate that those masons who gain experience in ergonomic safety and productivity in tandem are more likely to remain in the workforce beyond the 5-year mark. Thus, it is essential to alter apprentice training to guarantee this outcome. (C) 2017 American Society of Civil Engineers.