Trimble M H, Koceja D M
Indiana University School of Medicine, Department of Physical Therapy, Indianapolis 46202-5119.
Int J Neurosci. 1994 Jun;76(3-4):293-303. doi: 10.3109/00207459408986011.
Thirteen neurologically healthy adults were asked to balance on a specially designed balance board. This board allowed rotation in the sagittal plane only. Muscle activity of the triceps surae and tibialis anterior was sampled at 2 kHz and recorded. When the subject was balanced, soleus H-reflexes were elicited in the right leg with a constant-current stimulus pulse. The peak to peak amplitude of the soleus H-reflex served as the perturbation to the subject's balance as well as the dependent variable in question. Subjects performed three blocks (7 H-reflexes/block) of standing control trials with the balance board supported, and seven blocks of balancing trials. Prior to each block, maximal M-waves were recorded to ensure electrode stability across blocks. Results indicated that the subjects were able to significantly reduce (p < .001) the gain the soleus H-reflex while balancing and after the balance training. As a group, the subjects decreased their peak to peak amplitude of the soleus H-reflex by 26.2 percent from the initial standing block to the last balancing block. Moreover, subjects were also able to significantly reduce the gain of their standing control H-reflexes, supporting the notion of longer-term adaptability of the spinal stretch reflex. It is concluded that the progressive reduction in the H-reflex gain with short-term training may represent functional adaptation in the central nervous system.
13名神经系统健康的成年人被要求站在一个特别设计的平衡板上保持平衡。这个平衡板仅允许在矢状面内旋转。以2千赫兹的频率对小腿三头肌和胫骨前肌的肌肉活动进行采样并记录。当受试者保持平衡时，用恒流刺激脉冲在右腿诱发比目鱼肌H反射。比目鱼肌H反射的峰峰值幅度作为对受试者平衡的干扰以及所研究的因变量。受试者在平衡板得到支撑的情况下进行了三个站立控制试验组（每组7次H反射），以及七个平衡试验组。在每个试验组之前，记录最大M波以确保跨试验组电极的稳定性。结果表明，受试者在平衡过程中和平衡训练后能够显著降低（p < 0.001）比目鱼肌H反射的增益。作为一个群体，受试者的比目鱼肌H反射峰峰值幅度从最初的站立试验组到最后的平衡试验组降低了26.2%。此外，受试者还能够显著降低其站立控制H反射的增益，支持了脊髓牵张反射具有长期适应性的观点。得出的结论是，短期训练后H反射增益的逐渐降低可能代表中枢神经系统的功能适应。
