骶棘肌的肌电

ELECTROMYOGRAPHIC STUDIES OF THE M.SACROSPINALIS

本文以Ediswan脑电机表面电极及针电极,观察了在各种姿势和运动中骶棘肌的活动。一、舒适放松站立位时,骶棘肌电位无活动。立正站立位骶棘肌有“明显”电位活动。二、直立位后伸躯干时,先有一爆发性收缩,随身体后仰而消失。由已伸的姿势前屈至直立位过程中亦未有电位活动。三、自直立位前屈时,出现“明显”电位活动,至30度左右的“临界点”时,电位突然消失,进一步完全充分屈曲亦无活动,在此姿势中起伸,直到再度达“临界点”才复出现活动。四、舒适放松坐位及充分蹲下位时,能棘肌无活动。五、自直立位侧屈躯干时,对侧骶棘肌出现电位活动而本侧无活动。六、走步时,除前步末期及支撑腿垂直瞬间无电位活动外,其他各运动相都有活动。七、结合模拟农民插秧及锉工站立作业姿势动作进行了肌电观察。八、对骶棘肌在脊柱屈曲及伸直运动中的作用,结合临床等方面进行了初步讨论。并提出了粗浅的预防腰背劳损措施的建议。

1.The actions of the m.sacrospinalis in the lumbar region were studied in five human subjects by electromyographic techniques with surface and needle electrodes.2.Extension of the trunk from an upright position was usually initiated by a short burst of m.sacrospinalis activity and then the extension was checked by the m.rectus abdominis.Flexion of the trunk from the above position was activated by the m.rectus abdominis;whereas the m.sacrospinalis showed no activity whatever.In bending the trunk forward from an upright position activity was recorded in the m.sacrospinalis.And as the bending progressed there was a gradual increase in the activity of the m.sacrospinalis which ceased abruptly before the full trunk flexion was complete.This point at which activity cease is commonly known as the"critical point".Upon extension of the trunk from fully flexed position,the m.sacrospinalis showed no activity;until once again the"critical point"was reached there appeared marked activity in the m.sacro-spinalis which continued until the standing position was resumed.3.During lateral flexion of the trunk from an upright position only the contra-lateral m.sacrospinalis manifested marked activity.Upon rotation the m.sacrospinalis on both sides became active,but more activity was observed in the ipsilateral m.sacro-spinalis than in the contralateral.4.No activity was recorded in the m.sacrospinalis on sitting,full squatting and standing-at-ease.5.Observations were also made of the m.sacrospinalis activity in walking,in posi-tions imitating paddy-planting of a farmer,and the filing action of a worker in a standing position.