以VDTlog軟體評估電腦工作者上肢肌肉疲勞情形

Using the VDTlog Software to Evaluate Upper-extremity Musclar Fatigue of Computer Users

王甄伶(Chen-Ling Wang)

指導教授 ： 黃耀輝

國立臺灣大學/公共衛生學院/職業醫學與工業衛生研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.01938

摘要

雖然已經有許多報告顯示電腦工作者和上肢肌肉骨骼疾病的相關性，但較少使用客觀的監測系統評估實際職場中電腦工作者使用電腦狀況及肌肉疲勞情形的研究。而在先前的研究發現，電腦活動紀錄軟體VDTlog所記錄之參數中，滑鼠移動之速度與加速度和表面肌電圖量測之頻率參數的變化有一致性，可考慮用來當成操作滑鼠動作表現的評估指標。本研究目的分為兩部分，第一部分為利用VDTlog軟體與表面肌電圖為評估工具，探討表面肌電圖量測結果與VDTlog軟體記錄結果的相關性，找出適合用於評估實際職場電腦工作者肌肉疲勞之指標。第二部分則將VDTlog軟體運用於評估實際職場上電腦工作者肌肉疲勞的情形，並探討電腦工作者的上肢肌肉骨骼症狀的發生情形與可能原因。
本研究第一部分募集30位過去一年無上肢肌肉骨骼相關病史之男性受試者，在人因工程實驗室中，連續以滑鼠操作一種電腦遊戲兩小時。量測受試者表面肌電圖資料及利用VDTlog軟體來記錄鍵盤及滑鼠之操作情形，分析兩小時內受試者之肌電圖振幅、中位頻率等參數與VDTlog所記錄之滑鼠移動速度及加速度之各百分位的變化及相關性。結果顯示，滑鼠移動速度第99百分位（P<0.05）、第1百分位（P<0.005）和加速度的第99百分位（P<0.005）、第95百分位（P=0.02）、第90百分位（P=0.04）、第5百分位（P=0.03）、第1百分位（P<0.005）及伸指肌中位頻率（P<0.0001）在第一小時與第二小時之間有顯著差異。而由Mixed Model合併分析VDTlog所紀錄之滑鼠移動速度和加速度與肌電圖各量測肌肉之振幅、中位頻率之關係結果顯示，滑鼠移動加速度之第95百分位、第90百分位、第5百分位數值可用來替代伸指肌之肌電圖參數變化，作為評估電腦工作者肌肉疲勞的指標。
本研究第二部分募集39位使用電腦工作為主的職場員工，利用VDTlog軟體記錄受試者日常工作的電腦作業活動，共記錄5個工作天，並收集基本資料問卷、人體計測及工作站環境資料。結果顯示，受試者自我評估使用電腦時間（7.32±1.83小時）比VDTlog記錄使用電腦時間（3.34±1.42小時）有顯著高估情形（P<0.0001）；，使用滑鼠的時間長度與肩膀疼痛自覺症狀呈正相關（OR=4.43，95%信賴區間：1.23~33.17，P=0.03）；使用電腦、滑鼠、鍵盤時間與滑鼠移動速度及加速度呈負相關（P<0.05），電腦閒置時間與滑鼠移動速度呈正相關（P=0.01）；滑鼠移動加速度可被考慮用來作為評估手臂肌肉疲勞的指標。對於造成電腦工作者上肢肌肉骨骼症狀的危險因子，本研究和過去研究有類似的發現，但VDTlog記錄軟體所衍生的參數能較準確客觀地量化評估受試者電腦的使用情形，釐清不同輸入工具（鍵盤、滑鼠）個別的使用時間，且對受試者工作的干擾較小；利用VDTlog記錄軟體所得的滑鼠移動加速度評估受試者手臂肌肉的疲勞情形為一更便利、即時且節省成本的評估方法。本研究驗證了利用VDTlog軟體評估實際職場上電腦工作者肌肉疲勞情形的可行性，未來期望進一步將VDTlog軟體運用於大量樣本或長期監測的流行病學研究中。

關鍵字

電腦工作 ； VDTlog ； 肌肉疲勞 ； 肌電圖

並列摘要

Extensive computer use is an identified risk factor for computer work-related musculoskeletal disorders. However, only limited studies used objective measurements to assess the association between computer work loadings and musculoskeletal fatigue in field study. Previous studies reported that derived electronic activity recording parameters, i.e., mouse moving speed and acceleration of the VDTlog monitoring system, were correlated with the median frequency of surface electromyogram (sEMG) measurement, and therefore could be considered as indicators for computer mouse users’ performance evaluation. The objectives of this study were: (1) to correlate the measurements with sEMG and VDTlog monitoring system, respectively, for continuous computer work in order to identify appropriate indicators for the upper-extremity musclar fatigue, and (2) to apply VDTlog monitoring system in field study to evaluate the upper extremity musculoskeletal fatigue of the computer users and explore the possible causes for the occurrence of upper extremity musculoskeletal discomforts.
In the first part of this study, there were 30 male subjects recruited who didn’t have musculoskeletal disorders in the upper extremity in the past year. All subjects were asked to play a computer game continuously for two hours in an ergonomics laboratory. sEMG was used to monitor the activities of extensor digitorum communis (EDC), flexor digitorum superficialis (FDS), and bilateral upper trapezius during the computer game playing. Meanwhile, VDTlog monitoring system was also applied to record the electronic activities of computer mouse and keyboard operation. Statistical analysis on the amplitude and median frequency of sEMG measurement and various percentiles of derived speed and acceleration parameters for mouse movement with VDTlog monitoring system were conducted to characterize their distributions and explore the correlation among them. Results showed that the median frequency of EDC(P<0.0001), the first (P<0.005) and 99th (P<0.05) percentiles of mouse-moving speed and the 99th (P<0.005), 95th (P<0.02), 90th (P<0.04), 5th (P<0.03), 1st (P<0.005) percentiles of mouse-moving acceleration were significantly different between the 1st and 2nd hours in this two-hour game experiment. Mixed model analysis on the speed and acceleration parameters derived from VDTlog monitoring and the amplitude and median frequency of sEMG measurement indicated that the 95th, 90th and 5th percentiles of mouse-moving acceleration might be able to substitute median frequency of EDC as indicators for upper-extremity muscular fatigue of the computer users.
In the second part of this study, there were 39 computer workers recruited as study subjects. Their daily activities with computer at work in five consecutive days was recorded with VDTlog monitoring system. Questionnaire administration was conducted to collect study subjects’ personal information, while individual anthropometric data and work environmental layout were also obtained on site. Results indicated that the study subjects tended to overestimate their computer use time at work (7.32±1.83 hours) as compared to that recorded by VDTlog monitoring system (3.34±1.42 hours, p<0.0001）. The recorded mouse use time (OR=4.43, 95% CI: 1.23~33.17 for more than 2 h/day, p=0.03) were positively associated with shoulder discomforts. In contrast, the computer use time, mouse use time, and keyboard use time were negatively associated with mouse-moving speed and acceleration (p<0.05), while computer idle time (電腦閒置時間) was positively associated with mouse-moving speed (p=0.01). Accordingly, mouse-moving acceleration could be considered as an alternative indicator of upper extremity muscular fatigue for computer user. In conclusion, VDTlog monitoring system provided objective and reliable parameters for quantitative evaluation of computer work loading, in terms of use time by different computer input method, i.e., mouse and keyboard, with limited interference to the computer user. Furthermore, VDTlog features a convenient and cost-saving method for upper extremity muscular fatigue evaluation with VDTlog derived parameters, i.e., mouse-moving speed and acceleration. This study demonstrated the feasibility of applying VDTlog monitoring system in work place to evaluate the muscular fatigue of computer users. In the future, it is anticipated to further apply VDTlog monitoring system in large scale study or long term epidemiological surveillance.

並列關鍵字

computer work ； VDTlog ； muscular fatigue ； sEMG

參考文獻

49. 葉昭妤: 電腦鍵盤滑鼠活動紀錄系統效度測試。 國立台灣大學碩士論文 九十六。

48. 王慶翔: 電腦滑鼠活動記錄系統開發與測試。 國立台灣大學碩士論文 九十五年。

8. 張富涵: 持續性使用電腦滑鼠之上肢肌肉疲勞評估。 國立台灣大學碩士論文; 九十七年。

61. 黃健庭: 不同施力程度的疲勞性收縮對震顫特徵之影響。 國立成功大學碩士論文 九十六年。

47. 陳俊煌: KBlog 打字表現監測與前臂肌電圖之相關性探討。 國立台灣大學碩士論文 九十三年。