Evaluation of Upper-Extremity Muscle Fatigue Resulting from Continuous Use of Computer Mouse
| Autor: | Fu-Han Chang, 張富涵 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 Due to the prevalence of graphical user interface, the computer mouse has become an indispensable input device and is frequently used in the computer works. The aims of this study were to assess the upper-extremity muscle fatigue during the continuous computer mouse use by VDTlog monitoring system, EMG, and self-report for upper-extremity muscles fatigue, and to evaluate the correlation between VDTlog monitoring system and EMG in the fatigue assessment. There were 30 male subjects recruited who didn’t have musculoskeletal disorders of upper extremity in the past year. All subjects were asked to use computer mouse to play a computer game continuously for two hours in an ergonomics laboratory. The VDTlog monitoring system software program was installed in the computer to monitor the activities of computer mouse. EMG was used to monitor the activities of extensor digitorum communis (EDC), flexor digitorum superficialis (FDS), and bilateral upper trapezius during the computer game playing. At the beginning, the end of the first hour of playing game and the end of the second hour of playing, respectively, subjects were asked to assess the upper-extremity muscles fatigue by a self-report questionnaire. The results of joint analysis of EMG spectrum and amplitude (JASA) showed that all target muscles presented significant muscle fatigue by EMG measurement after two hours computer game playing, especially for the right upper trapezius of 9 and 10 muscles in the first and the second hour of computer game playing, respectively. After two-hour computer game playing, it was also found that the extent of self-report fatigue of all parts of upper-extremity increased along with time, especially for the shoulder, neck and eyes, with average scores were 3.7, 3.5 and 4.4, respectively. Besides, the results of VDTlog monitoring showed that mouse movement accounted for the most frequency of mouse activities during the computer game playing, 48% of all mouse actions. The average velocity of mouse movement in the first and the second hours of computer game playing were 0.72 pixel/ms and 0.71 pixel/ms, respectively, and the 99 percentile acceleration were 0.130 pixel/ms2 and 0.125 pixel/ms2. The average velocity and the 99 percentile acceleration were slower in the second hour of computer game playing. The average velocity and maximum acceleration of mouse movement also presented similar trends along the time, and may be used as performance indicators for mouse activities. Combined analysis of VDTlog with EMG, we found that the median frequency of flexor digitorum superficialis (FDS) was correlated with the VDTlog related indicators, for example, positively correlated with the average velocity of mouse movement and negatively correlated with the key holding time of left button clicking, right button clicking and dragging activities. It’s concluded that VDTlog monitoring system is able to assess the activities and performance of computer mouse use by the change in velocity or acceleration of mouse movement. VDTlog can also be combined with EMG to assess the upper-extremity muscle fatigue resulting from continuous use of computer mouse. Since it won’t interfere with the computer works and is convenient to operate, VDTlog is anticipated to be used in field study to generate more useful indicators in order to evaluate the muscle fatigue resulting from continuous computer works. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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