Measuring various sizes of H-reflex while monitoring the stimulus condition.
The purpose of this study was to assess the usefulness of a new technique that measured various sizes of the soleus H-reflex, while monitoring the stimulus condition. Eight healthy volunteers participated in this experiment. In the new technique, an above-motor-threshold conditioning stimulus was given to the tibial nerve 10-12 ms after a below-motor-threshold test stimulus. The conditioning stimulus evoked a direct M-wave, which was followed by a test-stimulus-evoked H-reflex. This reflex was followed by a conditioning stimulus-evoked H-reflex. The amount of the voluntary-contraction-induced facilitation of the H-reflex was similar for both the new technique and conventional technique, in which an above-motor-threshold test stimulus was given without a conditioning stimulus. Using the new technique, we found that the amount of facilitation increased linearly with the size of the test H-reflex. This technique allows us to evoke various sizes of H-reflex while monitoring a stimulus condition, and is useful for measuring H-reflexes during voluntary movement.
Hiraoka
Koichi
K
Department of Physical Education and Welfare Okayama Prefectural University-Junior College, 111 Kuboki, Sojya, Okayama 719-1197. hiraoka@ojc.oka-pu.ac.jp
D000293:Adolescent; D000328:Adult; D003213:Conditioning, Psychological / Q000502:physiology*; D004558:Electric Stimulation; D004576:Electromyography / Q000295:instrumentation; D005260:Female; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology