Hsieh Yao-Jen, Cho Chiung-Yu
Graduate Institute and Department of Physical Therapy, Medical College, National Cheng Kung University, No. 1 Ta-Hsueh Road, Tainan 701, Taiwan.
Eur J Appl Physiol. 2008 Sep;104(1):9-17. doi: 10.1007/s00421-008-0767-x. Epub 2008 May 27.
Most of previous studies use questionnaire to assess risk factors for cumulative trauma disorders of the upper extremity (CTDUE) for computer workers. Few studies combine both physical examination and questionnaire to assess musculoskeletal symptoms. Fifteen symptomatic and 15 non-symptomatic computer users were recruited. Both of them were asked to perform a repetitive tapping task (200 taps/min) as the fatigue task. Tremor of the index finger and surface electromyography (EMG) of the flexor digitorum superficial (FDS) were collected prior and after the tapping task. Muscle strength and range of motion for right wrist were collected before the tapping task. All subjects were asked to fill out the questionnaire about risk factors of CTDUE. Female users in the symptomatic group had weaker wrist extensor strength than those in the non-symptomatic group (P < 0.05). After performing the tapping task, FDS strength and median frequency of the FDS EMG at 25%, and 100% maximal voluntary contraction (MVC) for the symptomatic group decreased (P < 0.05). However, no significant differences were found in strength and median frequency of the FDS EMG between prior and after tapping task in the non-symptomatic group. There was no significant difference for root mean square of the finger tremor between and within groups. Regression analysis revealed that median frequency of the FDS EMG at 25% MVC, age, total time spent on computer, and mouse position were better factors to classify computer users into the symptomatic group compared to other factors obtained from questionnaire and physical exam. Besides, symptomatic computer users seem to have longer experience of computer use than non-symptomatic users. After the fatigue task, the symptomatic users decreased their muscle strength to a larger extent than the non-symptomatic users.
先前的大多数研究使用问卷来评估计算机工作者上肢累积性创伤障碍（CTDUE）的风险因素。很少有研究将体格检查和问卷结合起来评估肌肉骨骼症状。招募了15名有症状和15名无症状的计算机用户。他们都被要求执行一项重复敲击任务（每分钟200次敲击）作为疲劳任务。在敲击任务前后收集食指震颤和指浅屈肌（FDS）的表面肌电图（EMG）。在敲击任务前收集右手腕的肌肉力量和活动范围。所有受试者都被要求填写关于CTDUE风险因素的问卷。有症状组的女性用户手腕伸肌力量比无症状组的女性用户弱（P<0.05）。执行敲击任务后，有症状组的FDS力量以及FDS EMG在25%和100%最大自主收缩（MVC）时的中位频率降低（P<0.05）。然而，无症状组在敲击任务前后FDS EMG的力量和中位频率没有显著差异。组间和组内手指震颤的均方根没有显著差异。回归分析显示，与从问卷和体格检查中获得的其他因素相比，FDS EMG在25%MVC时的中位频率、年龄、在电脑上花费的总时间以及鼠标位置是将计算机用户分类为有症状组的更好因素。此外，有症状的计算机用户似乎比无症状用户有更长的计算机使用经验。在疲劳任务后，有症状的用户比无症状的用户肌肉力量下降的程度更大。
