Postural Analysis of Four Jobs on Two Building Construction Sites: an Experience of Using the OWAS Method in Taiwan

Postural Analysis of Four Jobs on Two Building Construction Sites: an Experience of Using the OWAS Method in Taiwan: Kai Way LI, et al. Department of Industrial Management, ChungHua University—Ovako Working Postures Analysing System (OWAS) is a widely used method for studying awkward working postures in workplaces. This study with OWAS, analyzed 2,880 working postures for form, scaffold, iron, and cement works at two building construction sites in northern Taiwan. A computer program, CCOWAS, was designed for the study. It was found that more than 30% of the working postures observed were classified as either AC2 (slightly harmful), AC3 (distinctly harmful), or AC4 (extremely harmful). The percentage of harmful postures for scaffold workers was even as high as 43.3%. Postures that needed to be corrected either soon (AC3) or immediately (AC4), and corresponding tasks, were identified. The most stressful tasks observed were sawing, positioning and hammering of the forms for form workers; positioning and wire-tying of iron rods for iron workers; brick-laying for cement workers; and manual handling of steel frames in confined spaces for scaffold workers. Improvement of these tasks was discussed. Some hand-intensive activities, such as wire-tying of iron work, were observed. The unnatural hand postures of these activities could not be recorded by means of OWAS. It was therefore recommended that incorporation of hand postures into basic OWAS or the use of supplementary methods is required to identify ergonomic risk factors for iron work or other hand-intensive activities on local construction sites. (J Occup Health 1999; 41: 183–190)