Biomechanics Laboratory, College of Physical Education, Shandong Normal University, 88 Wenhua East Road, Jinan, Shandong 250014, China.
Gait Posture. 2014 Jan;39(1):161-5. doi: 10.1016/j.gaitpost.2013.06.019. Epub 2013 Jul 16.
Investigations corresponding to the affected factors of the cross-correlation of pair muscles are limited though muscle activation patterns of bilateral erector spinae (ES) during trunk flexion-extension performance in standing have been utilized as an indicator in the evaluation of low back pain condition. The purpose of the study is to evaluate the effect of leg support on the cross-correlation of bilateral ES, and to test if the average of bilateral ES could weaken this effect. Twenty male university students volunteered for this study. Each performed the trunk flexion-extension in three leg support conditions randomly with the condition of single left leg support, double leg support and single right leg support, respectively. Each condition included three trials of trunk flexion-extension with the cycle of 5s flexion and 5s extension in standing. Surface electromyography from the right ES muscle as well as from the left one was recorded. The cross-correlation both in pair muscle of right-left ES and in pair muscle of right-average of bilateral ES was calculated in the flexion as well as extension period. A one-way ANOVA with repeated measures was used. The results showed that leg support has some effect on cross-correlation of bilateral ES, which causes the absolute value of phase lag to be significantly larger in flexion period. It is suggested that this effect could be weakened by the average of bilateral ES through significantly increasing the cross-correlation coefficient, and decreasing the absolute value of phase lag.
尽管在站立位屈伸运动中双侧竖脊肌（ES）的肌肉激活模式已被用作腰痛评估的指标，但对于双侧 ES 交叉相关的影响因素的研究仍很有限。本研究旨在评估腿部支撑对双侧 ES 交叉相关的影响，并检验双侧 ES 的平均值是否会削弱这种影响。20 名男性大学生自愿参加了这项研究。他们分别在单左腿支撑、双腿支撑和单右腿支撑三种腿部支撑条件下随机进行了三次屈伸运动，每次运动持续 5 秒屈和 5 秒伸，每个条件下的运动都包含三个周期。在站立位上记录右侧 ES 肌肉以及左侧 ES 肌肉的表面肌电图。在屈伸过程中，计算双侧 ES 对侧肌肉和双侧 ES 平均值对侧肌肉的交叉相关。采用重复测量的单向方差分析。结果表明，腿部支撑对双侧 ES 的交叉相关有一定影响，这导致在屈伸过程中相位滞后的绝对值明显增大。通过显著增加交叉相关系数和减小相位滞后的绝对值，双侧 ES 的平均值可以减弱这种影响。
