Power grip strength as a function of tool handle orientation and location

Abstract

Thirty male volunteers participated in a study evaluating the effect of workspace envelope (work height and reach distance) and handle orientation on grip force capacity. Maximum voluntary power grip exertions were recorded using instrumented tool handles under three conditions: a pistol grip tool handle oriented horizontally and vertically and a right angle tool handle oriented horizontally. Significant main effects of handle height and reach location on normalized grip force capacity were observed with the horizontally oriented pistol grip and right angle handles, whereas only an interaction effect was observed with the vertically oriented pistol grip handle. Comparison of results to scores produced with a job assessment tool (RULA) is included as an appendix. The proposed methodology can provide information useful to job, workstation or tool design directed toward best accommodating the physical capacities of workers performing hand tool tasks.

Keywords:

• Maximum voluntary exertion
• Hand tool
• Workspace envelope
• RULA

Acknowledgement

The authors would like to thank Michael Blair, M.M.S. for his assistance with the ergonomics evaluation. Funding for this project was provided by the Liberty Mutual Research Institute for Safety, Hopkinton, MA, USA.