Background: Construction workers are at greater risk of musculoskeletal disorders due to their exposure to physical ergonomic risk factors.
Objectives: The purpose of this study is to quantify the ergonomic hazards for workers in the construction of residential buildings.
Methods: In this cross-sectional study, PATH method, a work-sampling observation method, was applied to study the working postures, handled loads, and manual material handling activities in construction workers. A total of 5832 observations were made on 10 workers involved in tasks of three jobs including reinforcing bar, formwork, and pouring concrete. The ergonomic exposure was characterized in terms of percentage of observations made for each task.
Results: Non-neutral trunk postures, especially mild and severe flexions, were frequently observed in all job tasks. High-strain leg postures of squatting, kneeling, and leg(s) bent were mostly observed in floor formwork (39%), concrete finishing (5%), and floor rebar construction (52.3%), respectively. The highest proportion of work time with one (5.8%) and two hands (9%) at/above shoulder was observed in column rebar construction. In concrete pouring and rebar cutting, workers were observed in 39.45% and 23.1% of work time doing carry and push/pull activities, respectively. Heavy loads (>15 kg) were mostly observed in concrete pouring and floor formwork tasks.
Conclusion: In the construction of residential buildings with the concrete structure, workers perform their task with non-neutral postures of trunk and leg and handling heavy loads. The recommended controls could reduce the musculoskeletal stress in rebar tying, concrete pouring, and concrete finishing tasks.
Keywords: Construction industry; material handling; observation; posture analysis.