Abstract
The objective of this study is to evaluate the effects of wearing a glove and wrist support on hand-arm response while operating an in-line pneumatic screwdriver. Hand-arm response was investigated in terms of triggering finger force, flexor digitorum EMG and hand-transmitted vibration. Four glove levels (barehanded, cotton, nylon and open-finger), and two wrist support levels (wearing, and not wearing) were evaluated. Thirteen healthy male subjects drove screws into a horizontally mounted iron plate with pre-tapped screw holes using an in-line pneumatic screwdriver in the randomly ordered experimental conditions. The results indicate that wearing a nylon glove and not using a wrist support is the best combination among the eight evaluated experimental conditions. Wearing a nylon glove reduced 18.2% of the triggering force as compared with the barehanded condition. In addition, wearing a nylon glove had comparatively low forearm muscular exertion, and reduced 16% and 15% of hand-transmitted vibration in the z-axis and the sum of 3-axes as compared with the barehanded condition. The use of a wrist support required a greater triggering force and a 9.9% greater hand-transmitted vibration in the y-axis than when not using a wrist support. Relevance to industry - The results of this study can be applied to the design of assembly tasks in the electronic industry to reduce the risk of incurring upper extremity cumulative trauma disorders. Copyright (C) 1999 Elsevier Science B.V.