An assembly organization's approach to conducting ergonomics assessments of nutrunners in the absence of standards

Abstract

Repetitive use of handheld nutrunners contributes to the development of musculoskeletal disorders (MSDs) among assembly operators. Tool-using organizations control the physical exposures resulting from nutrunners through their own, company-specific methods and recommendations. The aim of this study was to explore an automotive organization's current practice when conducting ergonomics assessments of nutrunner use. Fourteen employees representing different professional roles within the automotive manufacturing organization were interviewed about their involvement in, and approaches to, ergonomics evaluations of nutrunners. Findings show that the objective criteria tightening torque and tool type are combined with the operators' subjective assessments of the load to identify MSD risks associated with nutrunner use. This way, the effects of factors such as working posture could be integrated into the assessment. Further, it was found that information and knowledge availability could influence the resulting exposures estimates, where for example information about how to appropriately select tool settings is not readily available. In addition, there are negotiating criteria such as quality considerations which need to be balanced with health and safety management, influencing the physical demands associated with power tools. Relevance to industryBy providing insight into an automotive manufacturer's approach to managing and assessing handheld tightening tools, policy-makers can form recommended limits and methods for standardized assessments of reaction load exposure from nutrunners.