Citation

Willms K, Wells R, Carnahan H. Hum. Factors 2009; 51(6): 797-812.

Copyright

(Copyright © 2009, Human Factors and Ergonomics Society, Publisher SAGE Publishing)

DOI

10.1177/0018720809357560

PMID

unavailable

Abstract

Objective: To determine the contribution of the loss of tactile sensitivity, glove flexibility, glove thickness, and changes in finger geometry to force decrement and increased effort during gloved power grip. Background: Gloved work has been shown to increase the effort required to perform manual tasks. Method: A battery of maximal and submaximal gripping tasks was performed while grip force and surface electromyography of seven forearm muscles were recorded. Participants performed power grips while wearing three different thicknesses of rubber gloves (differing only in thickness; maximum 3.1 mm), wearing interdigital spacers between the fingers (matched to the glove thicknesses), and with a bare hand. Results: Decreases in maximum grip force compared with the bare hand were observed for the thickest glove (—31.0 ± 6.8%, p < .05) and for the thickest interdigital spacers (—9.7 ± 5.9 %, p < .05). Participants increased their grip force with increasing glove thickness for a submaximal object-lifting task (p < .01). To maintain an unloaded grip posture and to create a fixed submaximal force, participants increased muscle activation (p < .05) for all muscles with increasing glove thickness. Conclusion: Decreases in maximal grip force and increased effort in submaximal tasks could be attributed to a combination of reduced tactile sensitivity, the effort to bend the gloves, and interdigital separation. Application: Although the values obtained are specific to the rubber gloves tested, the results give insights into factors important in the design and selection of gloves.