Risk, Postural and Physical Strain Assessment of Sawmill Workers in Nigeria

Abstract

Work-related Musculoskeletal Disorders (WMSDs) have been seen as major health problems that have direct impacts on workers’ physical/psychosocial well beings, health, and productivity. Thus, the assessment of Musculoskeletal Disorders (MSDs) in sawmills will lead to a suitable platform for development and execution of proper ergonomic intervention programmes to achieve desirable workplaces. This research focused on determining the prevailing factors associated with MSDs and establishment of exposure’s level of sawmill workers to MSDs, based on risk and postural analyses using Quick Exposure Check (QEC), Rapid Entire Body Assessment (REBA) and Rapid Upper Limb Assessment Method (RULA); and physical strain assessment using relative Cardiovascular Load (% CVL), Cardiovascular Strain (% CVS) and Relative Heart Rate (%RHR) equations. Six hundred and sixty – three (663) male and thirty – three (33) female workers participated in the research survey and the participants were classified into two groups: machine operators’ classification (which included: Band-saw Operators (BOs), Circular-saw Operators (COs) and Planer Operators (POs)) and sawmill workers’ classification (which included: Machine Operators (MOs), Mill Workers (MWs), Dust Parkers (DPs); and Machine Maintenance Personnel (MMPs)). Ninety – six (96) workers each from each machine operators’ classification group (making 288 MOs), 240 MWs, 96 DPs, and 72 MMPs were considered for this study. Two cities were considered in each six Southwestern States of Nigeria, namely: Ekiti, Lagos, Ogun, Ondo, Osun, and Oyo States and a minimum of two sawmills were used in each city. The results of the postural analysis using QEC, REBA, and RULA show that an appreciable number of workers were working above the secured limit. Physical strain assessment results showed that not less than 60% of the workers were operating under high or very high-level discomfort and 61.8% of the workers were subjected to either heavy or very heavy work intensity.