title: H reflex amplitude. Effect of leg muscle activity.
abstract: The H reflex is a monosynaptic reflex whose latency can be used to evaluate pathology of the S1 nerve root and axon. Little has been written about the use of the H reflex amplitude in evaluating S1 nerve root and axon. Little has been written about the use of the H reflex amplitude in evaluating S1 nerve physiology. Although amplitude measurement of evoked potentials is useful in the evaluation of other sensory and compound muscle action potentials, this single case study shows it to be an unreliable parameter with which to evaluate the integrity of S1 nerve fibers, because muscle activity in antagonist and agonist affects the amplitude and in some instances abolishes it.
authors.affiliation: Premier Orthopedics and Sports Medicine, Nashville, Tennessee, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: McHugh
authors.forename: J C
authors.initials: JC
authors.lastname: Reeser
authors.forename: E W
authors.initials: EW
authors.lastname: Johnson
mesh_terms: D000200:Action Potentials; D000328:Adult; D001369:Axons / Q000502:physiology; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation*; D011237:Predictive Value of Tests; D013126:Spinal Nerve Roots / Q000503:physiopathology*