Park Soohee
Department of Occupational Therapy, Health Science College, Honam University, Republic of Korea.
J Phys Ther Sci. 2013 Dec;25(12):1529-31. doi: 10.1589/jpts.25.1529. Epub 2014 Jan 8.
[Purpose] This study investigated the difference in muscle activation of the dominant upper extremity in right-handed and left-handed persons during writing. [Subjects] There were 36 subjects (16 left- handers/ 20 right- handers), and the study was conducted from 03/01/2012 to 30/3/2012. [Methods] Six electrodes were attached to the FCU (flexor carpi ulnaris), FCR (flexor carpi radialis), ECU (extensor carpi ulnaris), ECR (extensor carpi radialis), and both UT (upper trapezius) muscles. [Results] FCU muscle activation was 16.77±9.12% in left-handers and 10.29±4.13% (%MVIC) in right-handers. FCR muscle activation was 19.09±9.43% in left-handers and 10.64±5.03% in right-handers. In addition, the UT muscle activation on the writing hand side was 11.91±5.79% in left-handers and 1.66±1.19% in right-handers. [Conclusion] As a result of this study, it was discovered that left-handers used more wrist flexion in performance of the writing task with the dominant upper extremity than right-handers, and that the left-handers activated the wrist and shoulder muscles more than the right-handers. These results indicate a potential danger of musculoskeletal disease in left-hander.
[目的] 本研究调查了右利手和左利手者在书写过程中优势上肢肌肉激活情况的差异。[对象] 共有36名受试者（16名左利手/20名右利手），研究于2012年3月1日至2012年3月30日进行。[方法] 将六个电极分别贴于尺侧腕屈肌（FCU）、桡侧腕屈肌（FCR）、尺侧腕伸肌（ECU）、桡侧腕伸肌（ECR）以及双侧斜方肌上束（UT）。[结果] 左利手者FCU肌肉激活率为16.77±9.12%，右利手者为10.29±4.13%（%MVIC）。左利手者FCR肌肉激活率为19.09±9.43%，右利手者为10.64±5.03%。此外，书写手一侧的UT肌肉激活率在左利手者中为11.91±5.79%，在右利手者中为1.66±1.19%。[结论] 本研究结果发现，左利手者在使用优势上肢执行书写任务时比右利手者更多地使用腕部屈曲，并且左利手者比右利手者更多地激活腕部和肩部肌肉。这些结果表明左利手者存在肌肉骨骼疾病的潜在风险。
