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Updated: May 2, 2026
Terminal H-reflex Measurements in Mice
Published on: June 16, 2022
H-reflexes reduce fatigue of evoked contractions after spinal cord injury
Austin J Bergquist1, Matheus J Wiest, Yoshino Okuma
1Faculty of Physical Education and Recreation, E-488 Van Vliet Centre, University of Alberta, Edmonton, Alberta, Canada, T6G 2H9; Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada.
Introduction:
Neuromuscular electrical stimulation (NMES) over a muscle belly (mNMES) generates contractions predominantly through M-waves, while NMES over a nerve trunk (nNMES) can generate contractions through H-reflexes in people who are neurologically intact. We tested whether the differences between mNMES and nNMES are present in people with chronic motor-complete spinal cord injury and, if so, whether they influence contraction fatigue.
Methods:
Plantar-flexion torque and soleus electromyography were recorded from 8 participants. Fatigue protocols were delivered using mNMES and nNMES on separate days.
Results:
nNMES generated contractions that fatigued less than mNMES. Torque decreased the least when nNMES generated contractions, at least partly through H-reflexes (n = 4 participants; 39% decrease), and torque decreased the most when contractions were generated through M-waves, regardless of NMES site (nNMES 71% decrease, n = 4; mNMES, 73% decrease, n = 8).
Conclusions:
nNMES generates contractions that fatigue less than mNMES, but only when H-reflexes contribute to the evoked contractions.
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