Brooke J D, McIlroy W E, Collins D F
School of Human Biology, University of Guelph, Ont., Canada.
Brain Res. 1992 Jun 5;582(1):78-84. doi: 10.1016/0006-8993(92)90319-5.
Modulation of soleus H-reflex magnitude over a cycle of leg movement and the adjustment of controls to account for it were explored. During pedalling, H-reflex magnitudes in all nine subjects were highest in the power producing phase and lowest in recovery. Stimulation intensity was standardized. Compared to sitting, these reflexes were significantly depressed (P less than 0.05). The sitting condition was modified in one experiment, so that the angles of the limb joints and the contraction level of soleus were matched to their values, measured at 13 equi-spaced points, around the pedal cycle. This matching resulted in some modulation of the H-reflex around the pedal cycle, when sitting. When the contraction of tibialis anterior was added to these changes to the seated control, this modulation came closer to that seen during movement. Movement-specific modulation of the reflex was now harder to identify. These data raise the question of whether the three features presently used for matching are causative in the movement modulation of the soleus H-reflex and whether they represent effects arising from centrally descending or peripheral sources.
研究了比目鱼肌H反射幅度在腿部运动周期中的调制情况以及为考虑该情况而对控制进行的调整。在蹬踏过程中，所有九名受试者的H反射幅度在产生功率阶段最高，在恢复阶段最低。刺激强度已标准化。与坐姿相比，这些反射明显受到抑制（P小于0.05）。在一项实验中改变了坐姿，使肢体关节角度和比目鱼肌的收缩水平与在踏板周期周围13个等间隔点测量的值相匹配。这种匹配在坐姿时导致了踏板周期周围H反射的一些调制。当在这些对坐姿控制的变化中加入胫骨前肌的收缩时，这种调制更接近运动时观察到的情况。现在更难识别反射的运动特异性调制。这些数据提出了一个问题，即目前用于匹配的三个特征是否是比目鱼肌H反射运动调制的原因，以及它们是否代表来自中枢下行或外周来源的效应。
