Evaluation of Grip Force Exertions in Dynamic Manual Work
Autor: | Katharyn A. Grant |
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Rok vydání: | 1994 |
Předmět: |
Engineering
business.industry 05 social sciences Work (physics) 050105 experimental psychology Hand movements body regions Medical Terminology Work cycle Task (computing) 0501 psychology and cognitive sciences Grip force Laboratory experiment business 050107 human factors Simulation Strain gauge Medical Assisting and Transcription |
Zdroj: | Proceedings of the Human Factors and Ergonomics Society Annual Meeting. 38:549-553 |
ISSN: | 1071-1813 2169-5067 |
DOI: | 10.1177/154193129403801002 |
Popis: | An obstacle to the development of guidelines for reducing forceful hand movements is that manual force is not easily measured or estimated at the worksite, especially during highly dynamic activities. Grip force requirements during manual work are dependent not only on object weight, but also on the surface characteristics of the object and the task dynamics. In theory, it is possible to predict grip force requirements for manual tasks using Newtonian laws of physics; however few researchers have attempted to measure grip force during dynamic work, much less to compare actual grip force values to predicted levels. Therefore, a laboratory experiment was conducted to examine grip force exertions during two simulated industrial tasks. In each task, participants repetitively grasped and moved aluminum handles against varying levels of weight or resistance. Grip force was measured using a strain gauge mounted inside the handles. Results indicate that grip force varied continuously throughout each work cycle in response to changes in the motion of the hand/handle. The pattern of variation was consistent between subjects and could be approximated by a sinusoidal model. Greater interindividual variation in grip force exertion was observed when the task allowed greater flexibility in selecting a movement strategy. The results also indicate that subjects are more likely to “overshoot” the necessary grip force (i.e., apply more force than needed) at the initiation of movement, especially at lower weight levels. This study demonstrates that it is possible to predict variations in grip force during dynamic work, although further refinements in the procedure are needed. Use of modelling techniques will enable industrial designers to better estimate grip force requirements and to identify design strategies that will reduce the risk of musculoskeletal injury to the worker. |
Databáze: | OpenAIRE |
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