Title: Effect of grip, stroke rotation and handle size on discomfort for screwing task

Authors: Farheen Bano; Zulqernian Mallick; Abid Ali Khan

Addresses: Department of Mechanical Engineering, Jamia Millia Islamia, New Delhi-110025, India ' Department of Mechanical Engineering, Jamia Millia Islamia, New Delhi-110025, India ' Ergonomics Research Division, Department of Mechanical Engineering, Aligarh Muslim University, Aligarh-202002, UP, India

Abstract: The objective of this study was to investigate the effect of grip force, rotation of driving stroke and handle size of the screw driver in screwing task on human performance in terms of discomfort and productivity. There were two levels of grip force (loose and tight grip), three levels of rotation of driving stroke (30°, 60° and 90° in supine) and two levels of handle size of a screw driver (35 mm and 40 mm). Twelve male participants performed the screwing task with a Phillips-head screwdriver, to tighten the screws for two minutes in supination rotation for each combination. A visual-analogue-scale was used for recording discomfort and numbers of screws tighten for a given time span was a parameter for productivity. The discomfort was not found significantly affected by handle size. Stroke rotation was significant on discomfort; however, relatively high productivity was achieved at 60° and 90° stroke rotation compared to 30°.

Keywords: grip force; stroke rotation; discomfort score; productivity; driving stroke; handle size; screwdrivers; screwing tasks; human performance; human factors.

DOI: 10.1504/IJHFE.2012.052013

International Journal of Human Factors and Ergonomics, 2012 Vol.1 No.4, pp.390 - 407

Received: 22 Jun 2012
Accepted: 23 Sep 2012

Published online: 09 Feb 2013 *

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