Reaction force exposure for tightening tool users: A psychophysical based experimental study of electric right-angle nutrunners

A Mazaheri; M Forsman; R Haettel; L M Rose

doi:10.1016/j.apergo.2022.103776

Reaction force exposure for tightening tool users: A psychophysical based experimental study of electric right-angle nutrunners

Appl Ergon. 2022 Sep:103:103776. doi: 10.1016/j.apergo.2022.103776. Epub 2022 Apr 26.

Authors

A Mazaheri¹, M Forsman², R Haettel³, L M Rose⁴

Affiliations

¹ KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, Division of Ergonomics, Hälsovägen 11C, 141 57, Huddinge, Sweden; Atlas Copco Industrial Technique AB, Sickla Industriväg 19, 105 23, Stockholm, Sweden. Electronic address: mazaheri@kth.se.
² KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, Division of Ergonomics, Hälsovägen 11C, 141 57, Huddinge, Sweden; Institute of Environmental Medicine, Karolinska Institutet, 171 77, Stockholm, Sweden.
³ Atlas Copco Industrial Technique AB, Sickla Industriväg 19, 105 23, Stockholm, Sweden.
⁴ KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, Division of Ergonomics, Hälsovägen 11C, 141 57, Huddinge, Sweden.

PMID: 35483120
DOI: 10.1016/j.apergo.2022.103776

Abstract

Reaction forces from nutrunner tools constitute a risk of developing MSDs. However, recommendations for sustainable reaction force levels are lacking. The aim of this study was to inform recommendations regarding reaction load exposures from right-angle nutrunners. Through a psychophysics approach, experienced assembly workers subjectively assessed reaction loads when using a nutrunner in six combinations of tool tightening strategy, work-pace and screw-joint stiffness. Electromyography, tool and joint parameters were measured. Regardless of tightening strategy, joint stiffness and work-pace combinations, no large differences in acceptable tightening torque, peak reaction force, and handle displacement were observed. However, acceptable jerk and impulse differed substantially between the TurboTight® (high-acceleration) and QuickStep® (conventional) tightening strategies. Although the TurboTight® strategy overall showed reduced peak muscular activities compared to the QuickStep®, the participant-rated acceptable torque levels were similar, plausibly due to TurboTights' high jerk levels. Jerk and impulse are hypothesized to influence the perception of reaction loads.

Keywords: Assembly work; Electromyography; Ergonomics assessment; Power tools.

MeSH terms

Electromyography
Humans
Torque*