Modulation of the triceps surae H-reflex with training

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.

MeSH terms

  • Adolescent
  • Adult
  • Arm / innervation
  • Arm / physiology
  • Biomechanical Phenomena
  • Electric Stimulation
  • Electromyography
  • Humans
  • Motor Skills / physiology*
  • Muscle Contraction
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / physiology
  • Muscles / innervation
  • Muscles / physiology*
  • Neuronal Plasticity / physiology
  • Postural Balance / physiology*
  • Reflex, Stretch / physiology*