A Biomechanical Analysis of Work Postures of Operators of Sandcrete Block-Making Machines in Selected Sites in Ado-Odo, Nigeria

The sandcrete block-making business is a significant part of the construction industry in Nigeria. Despite its significance, the safety and well-being of workers in the production process have not received adequate attention. Hence, the aim of this study is to conduct an ergonomic assessment of the impacts of block-making processes on workers in selected sites in a Nigerian city, using biomechanical approach together with possible hazards workers are exposed. Five sandcrete block-making sites using machine compaction in selected sites were visited, and biomechanical assessment on the operators of the block-making machines conducted. In the evaluation, pictures and video of the operators, to observe the postures assumed when performing the moulding and compacting tasks, were taken. Then the Rapid Entire Body Assessment chart (REBA) was used to assess each posture using a Time-weighted average and oral interviews with questionnaires to highlight prevalent Work-related Musculoskeletal Disorders (WMSDs) that the workers were experiencing. The results of the interview indicated about 75% of the listed WMSD, of finger numbness, loss of strength in hand, blanching and lower back pain, were experienced by all the operators across the sites. The Time-weighted score of postures of operators on sites A to E of REBA assessment ranged from 5–7, indicating a medium risk level of inducing musculoskeletal disorder in the workers, thus needing further investigations for possible modification of workplace. From this study, the work environment of block-making process in Nigeria appeared risky and need further examinations for safety and well-being of the workers.