Wei Ying, Shan Xinhai
a College of Physical Education, Shandong Normal University , Jinan , China.
J Mot Behav. 2017 Jul-Aug;49(4):422-428. doi: 10.1080/00222895.2016.1219312. Epub 2016 Oct 14.
The authors' purpose was to test the effect of asymmetric hand lifting on muscular activation patterns of 3 bilateral extensors. Eighteen male university students without back pain were volunteered. Each performed flexion-extension randomly with conditions of right lifting, left lifting, and nonlifting. Surface electromyography from bilateral thoracic, lumbar erector spinae, and hamstring was recorded. The cross-correlation and relative intensity in paired muscles of bilateral extensors was calculated in flexion as well as extension period. The results showed that the cross-correlation coefficient was decreased and the phase lag as well as the relative intensity of bilateral extensors was increased significantly in thoracic level. The phase lag as well as the relative intensity of bilateral extensors was increased significantly in lumbar level. It was concluded that asymmetric lifting has a significant effect on muscular activation of bilateral extensors in thorax level, which causes the ipsilateral extensor to activate larger and longer. Asymmetric lifting also has some effect on muscular activation of bilateral extensors in lumbar level but with less extent than in thorax level, which causes contralateral extensor to activate larger and longer. Asymmetric lifting seems to have no significant effect on muscular activation of bilateral hamstring.
作者的目的是测试不对称单手举重对3组双侧伸肌肌肉激活模式的影响。18名无背痛的男性大学生自愿参与。每个人在右手举重、左手举重和不举重的条件下随机进行屈伸运动。记录双侧胸段、腰段竖脊肌和腘绳肌的表面肌电图。计算双侧伸肌成对肌肉在屈曲和伸展期的互相关和相对强度。结果表明，胸段水平双侧伸肌的互相关系数降低，相位滞后以及相对强度显著增加。腰段水平双侧伸肌的相位滞后以及相对强度也显著增加。研究得出结论，不对称举重对胸段水平双侧伸肌的肌肉激活有显著影响，导致同侧伸肌激活更大且时间更长。不对称举重对腰段水平双侧伸肌的肌肉激活也有一定影响，但程度小于胸段水平，导致对侧伸肌激活更大且时间更长。不对称举重似乎对双侧腘绳肌的肌肉激活没有显著影响。
