Chang Chih-Hung, Shih Yuh-Chuan
Department of Business Administration, Yuda Institute of Business Technology, Taiwan.
Appl Ergon. 2007 May;38(3):317-24. doi: 10.1016/j.apergo.2006.04.024. Epub 2006 Jun 27.
In various workplaces, gloves are commonly employed to protect the hands with the design rationale of 'the thicker the gloves, the better the protection'. Therefore, the present paper investigated the effects of glove thickness on hand performance and fatigue during two infrequent high-intensity gripping tasks, such as 5-s and sustained tasks. The hand performance was evaluated by maximum volitional contraction (MVC) and its associated time needed to reach the MVC (TMVC), and the total force generation (TFG) during the sustained task. The hand fatigue was assessed by MVC degeneration (DeltaMVC), the shift in time needed to reach the MVC (DeltaTMVC), and the maximal endurance time (MET) associated with the sustained task. Ten female subjects took part in the experiment voluntarily. The four-gloved conditions included bare hand, wearing one layer (Cotton-1), wearing two layers of cotton gloves (Cotton-2), and covering the handle with two layers of cotton glove and exerting with the bare hand (Covered-2). The results indicates that wearing gloves decreased the grip MVC, and the thicker the gloves, the less the grip MVC, but the wearing style did not change the MVC (Cotton-2 MVC was indifferent from Covered-2 MVC). As to muscular fatigue, on the other hand, wearing gloves did not affect DeltaMVC, MET, TMVC, or DeltaTMVC. Due to the greater bare-hand MVC and indifferent MET, bare-hand TFG was better than those conditions with gloves. Finally, the load specified here did not alter TMVC or DeltaTMVC, but the greater the load, the more strength degeneration (DeltaMVC) was induced.
在各类工作场所，人们普遍使用手套来保护手部，其设计理念是“手套越厚，防护效果越好”。因此，本文研究了在两项不常见的高强度抓握任务（如5秒任务和持续任务）中手套厚度对手部性能和疲劳的影响。通过最大自主收缩（MVC）及其达到MVC所需的相关时间（TMVC）以及持续任务期间的总力产生量（TFG）来评估手部性能。通过MVC退化（DeltaMVC）、达到MVC所需时间的变化（DeltaTMVC）以及与持续任务相关的最大耐力时间（MET）来评估手部疲劳。十名女性受试者自愿参与了该实验。四种戴手套的情况包括裸手、戴一层手套（棉质-1）、戴两层棉质手套（棉质-2）以及用两层棉质手套覆盖把手并用裸手施加力（覆盖-2）。结果表明，戴手套会降低抓握MVC，手套越厚，抓握MVC越低，但佩戴方式并未改变MVC（棉质-2的MVC与覆盖-2的MVC无差异）。另一方面，对于肌肉疲劳，戴手套并未影响DeltaMVC、MET、TMVC或DeltaTMVC。由于裸手的MVC更大且MET无差异，裸手的TFG优于戴手套的情况。最后，此处规定的负荷并未改变TMVC或DeltaTMVC，但负荷越大，诱发的力量退化（DeltaMVC）就越大。
