兔腓肠肌表面肌电信号与肌肉收缩及运动中枢的关系

背景:以往的验证实验均采用电刺激方法诱发肌肉收缩,施加电流的影响使接收到的表面肌电信号混有外来电流成分,无法有效分析其与肌肉收缩,特别是与高位运动中枢的关系.目的:观察新西兰兔腓肠肌表面肌电信号与肌肉收缩及高位、低位运动中枢的关系.方法:在新西兰兔清醒状态下通过针刺右侧跟腱诱发腓肠肌收缩,局麻清醒状态下离断右侧坐骨神经,分别在针刺跟腱、钳夹离断的坐骨神经远侧断端、针刺腓肠肌和被动活动腓肠肌时,检测腓肠肌表面肌电信号的强弱及类型.局麻下于L3 平面横断脊髓,针刺左侧跟腱诱发腓肠肌收缩,检测腓肠肌表面肌电信号的强弱和类型.结果与结论:正常状态下经针刺跟腱诱发腓肠肌随意收缩时,可接收到400 μV 、持续4 s 的宽底随意波;横断脊髓后针刺跟腱诱发的反射性腓肠肌收缩接收到的信号小于100 μV 、持续时间小于1 s;离断坐骨神经后刺激跟腱、神经和肌肉时,均未引起肌肉收缩,但可接收到强度小于10 μV 、持续时间小于0.5 s 的干扰波;被动活动关节牵拉腓肠肌时未检测到肌电信号活动.说明兔腓肠肌表面肌电信号产生于肌肉收缩之前,是以高位运动中枢为主、低位运动中枢为辅发放到肌肉的驱动电信号的综合,而非肌肉收缩本身产生.

Relations of surface electromyogram signal with muscle contraction and motor centers in rabbit gastrocnemius muscle

BACKGROUND:In the previous verification tests,muscle contraction is induced by electric stimulation.Therefore,the detected surface electromyogram signal is mixed with applied electric current.So the relations between surface electromyogram signal,muscle contraction and upper motor centers can not be fully analyzed,especially the latter one.OBJECTIVE:To assess the relations between surface electromyogram signal,muscle contraction and upper or lower motor centers in New Zealand rabbit gastrocnemius muscle.MET...