McGorry R W, Hsiang S M, Fathallah F A, Clancy E A
Liberty Mutual Research Center for Safety and Health, Hopkinton, Massachusetts, USA.
Spine (Phila Pa 1976). 2001 Feb 15;26(4):418-25. doi: 10.1097/00007632-200102150-00019.
Timing of activation of the hamstrings and erector spinae was assessed using surface electromyography.
To investigate the influence of posture and movement speed during trunk flexion-extension on the flexion-relaxation response and trunk muscle activation patterns.
The literature contains numerous reports on coactivity and synergistic behavior of major muscle groups during trunk flexion-extension. There are few reports on the timing of muscle activation.
Six subjects were recruited for a training session and six biweekly test sessions. Ten surface electromyogram electrodes and a lordosimeter were used to record timing of lumbar motion and muscle recruitment in the hamstrings and at four sites in the thoracolumbar region. A 3 x 2 within-subject factorial design was used to test the effects of posture and speed on activation patterns.
Patterns of muscle activation were found to be dependent on posture and the direction of movement. The flexion-relaxation response was pervasive in the lumbar region but was less consistent at the T9 and hamstring sites. Significant differences in the delay between electromyogram activation and lumbar motion were found for the standing postures at initiation of extension, in which activation progressed in the caudad-to-cephalad direction.
The flexion-relaxation response is ubiquitous in the lumbar erector spinae and is present in the hamstrings and lower thoracic erector spinae, although not consistently in all subjects. In standing, timing of activation differed significantly by site in extension but not in flexion. Muscle activation patterns and flexion-relaxation were consistent over six biweekly test sessions.
使用表面肌电图评估腘绳肌和竖脊肌的激活时间。
探讨躯干屈伸过程中姿势和运动速度对屈伸放松反应及躯干肌肉激活模式的影响。
文献中有大量关于躯干屈伸过程中主要肌肉群共同激活和协同行为的报道。关于肌肉激活时间的报道较少。
招募6名受试者进行一次训练课程和六次每两周一次的测试课程。使用10个表面肌电图电极和一个脊柱前凸测量仪记录腰椎运动时间以及腘绳肌和胸腰段四个部位的肌肉募集情况。采用3×2受试者内析因设计来测试姿势和速度对激活模式的影响。
发现肌肉激活模式取决于姿势和运动方向。屈伸放松反应在腰椎区域普遍存在，但在T9和腘绳肌部位不太一致。在伸展开始时的站立姿势中，发现肌电图激活与腰椎运动之间的延迟存在显著差异，其中激活从尾端向头端进展。
屈伸放松反应在腰段竖脊肌中普遍存在，在腘绳肌和下胸段竖脊肌中也存在，尽管并非在所有受试者中都一致。在站立时，伸展时不同部位的激活时间存在显著差异，而屈曲时则没有。在六次每两周一次的测试课程中，肌肉激活模式和屈伸放松反应是一致的。
