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Observations on the variability of the H reflex in human soleus
Author(s) -
Funase Kozo,
Miles Timothy S.
Publication year - 1999
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/(sici)1097-4598(199903)22:3<341::aid-mus6>3.0.co;2-r
Subject(s) - h reflex , soleus muscle , reflex , tibial nerve , afferent , stretch reflex , electromyography , triceps reflex , medicine , anatomy , anesthesia , neuroscience , physical medicine and rehabilitation , withdrawal reflex , psychology , skeletal muscle , stimulation
H reflexes were evoked in human soleus by stimulating the tibial nerve at a constant intensity. Each trial was then assigned to one of three groups on the basis of the amplitude of its H reflex; all trials in each group were then full‐wave rectified and reaveraged. There was a strong positive relationship between the amplitude of the H reflex and the level of electromyographic activity in the muscle at the time of onset of the H reflex, which reflects the activity of the motoneuronal pool when the afferent volley arrived. Thus, much of the variability of the H reflex is due to small changes in the level of activation of the motoneuronal pool during repeated trials. The steady torque preceding the H reflex was a poor predictor of the H‐reflex amplitude, presumably because of the delay between the changes in the electrical activity of motoneurons and the mechanical outcome thereof. © 1999 John Wiley & Sons, Inc. Muscle Nerve 22: 341–346, 1999