The relative contribution to the plantar-flexor torque of the soleus motor units activated by the H reflex and M response in humans

Nicola A. Maffiuletti, Alain Martin, Jacques Van Hoecke, Marco Schieppati

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This study proposes a method of quantifying the relative contribution to the plantar-flexor torque of soleus H and M responses evoked by tibial nerve stimulation. For ten subjects, the amplitude of the twitch produced by the H wave was plotted against the corresponding potential, for stimuli producing H without M (i.e. in the ascending portion of the H-recruitment curve). It was then assumed that the contribution of H to twitches produced by M plus H was similar for similar H waves on the curve-descending portion. Hence, the contribution of M was estimated, for the range of M waves including those accompanying H(max). The estimated mechanical contributions of H and M wave increase linearly with their potentials, the slope of the relationship being greater for H than M. The interpretation of this finding is discussed. A simple formula for assessing the contribution of the H wave to the twitch torque is given. Copyright (C) 2000 Elsevier Science Ireland Ltd.

Original languageEnglish
Pages (from-to)127-130
Number of pages4
JournalNeuroscience Letters
Issue number2
Publication statusPublished - Jul 14 2000



  • H reflex
  • Human
  • M response
  • Peak twitch tension
  • Soleus muscle
  • Twitch torque

ASJC Scopus subject areas

  • Neuroscience(all)

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