Intersession reliability of Hoffmann reflex gain and presynaptic inhibition in the human soleus muscle.
Hayes BT, Hicks-Little CA, Harter RA, Widrick JJ, Hoffman MA. Intersession reliability of Hoffmann reflex gain and presynaptic inhibition in the human soleus muscle.


OBJECTIVE
To determine the day-to-day reliability of Hoffmann reflex (H-reflex) gain and presynaptic inhibition of spinal reflexes in the human soleus muscle.


METHODS
Controlled trial.


METHODS
Research laboratory.


METHODS
Volunteers (N=30; mean +/- SD age, 23.4+/-3.9y; height, 175.64+/-10.87cm; mass, 84.50+/-24.18kg) with no history of lower extremity pathology and/or injury participated.


METHODS
Subjects lay prone with the head, shoulders, arms, and hips supported in a static position by a massage body pillow and the ankle positioned at 90 degrees . Recording electrodes were placed over the soleus and tibialis anterior muscle bellies, and the stimulating electrodes were positioned over the tibial nerve in the popliteal space and the common peroneal nerve near the fibular head.


METHODS
The H-reflex and motor wave recruitment curves were then measured and recorded. Presynaptic inhibition was also assessed in the soleus muscle, and a conditioning stimulation of the common peroneal nerve (1 x motor threshold = motor threshold) was used prior to soleus H-reflex measurement. Two testing sessions took place between 2 and 7 days, and each session occurred at the same time of day.


RESULTS
Assessments of H-reflex gain and presynaptic inhibition yielded test-retest reliability of R equal to . 95 and .91, respectively.


CONCLUSIONS
Measures of presynaptic inhibition and H-reflex gain (H slope/M slope) in the human soleus muscle are consistent and reliable day to day.
Hayes
Bradley T
BT
Department of Exercise and Sport Science, University of Utah, Salt Lake City, UT, USA. bradley.hayes@hsc.utah.edu
Hicks-Little
Charlie A
CA
Harter
Rod A
RA
Widrick
Jeffrey J
JJ
Hoffman
Mark A
MA
D000328:Adult; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D017729:Presynaptic Terminals / Q000502:physiology; D015203:Reproducibility of Results