Article

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. DESIGN: Controlled trial. SETTING: Research laboratory.
PARTICIPANTS: 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. INTERVENTIONS: 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. MAIN OUTCOME MEASURES: 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.

Langue : ANGLAIS