A new method for eliciting and studying H-reflexes in the human masseter.
A non-invasive method is presented for transmuscular stimulation of the masseteric nerve, using a frame to apply a cathode to the mandibular notch and an anode to the inside of the mouth. The H-reflex response was recorded using surface, macro and single motor-unit (SMU) electromyography (EMG) from the masseter. The latency of the reflex response representing the H-reflex in SMUs was determined from the cumulative sum of the peristimulus time histogram. This latency was then corrected using a spike-trigger averaging technique, where the SMU spikes were used as triggers and the macro EMG recording as the source. SMU latencies for the H-reflex in masseter were in the range 5.9-8.8 msec, whereas H-reflex latencies for surface EMG varied between 5.4 and 6.4 msec.
Scutter
S D
SD
Department of Physiology, University of Adelaide, Australia.
Türker
K S
KS
Yang
J
J
D000200:Action Potentials / Q000502:physiology; D000328:Adult; D004566:Electrodes; D004576:Electromyography / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000294:innervation / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D009339:Needles; D011930:Reaction Time / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors