title: Association between muscle architecture and quadriceps femoris H-reflex.
abstract: The purpose of the present study was to establish the relationship between muscle architecture and H-reflex recordings in quadriceps femoris muscle. H-reflexes were elicited in human quadriceps femoris muscle over a broad area of skin to document the shape and amplitude of the H-potentials. This, in combination with recording monopolar and bipolar H-potentials, was performed to determine the location and method for measuring maximum-amplitude H-reflexes. The influence of neural and peripheral factors on the H-potential during passive length changes was studied by comparing the amplitude of H-potentials to motor unit action potentials. Monopolar recordings of the H-potential were found to be preferable to bipolar recordings because of the reproducibility of shape and easier distinction between the M- and H-potentials. The location for recording maximum H-potentials was in the distal one third of the quadriceps femoris muscle, over the border between vastus lateralis and rectus femoris. The inferred relationship between H-potential amplitude and reflex excitability must be made with caution in quadriceps femoris muscle because the amplitude of both the motor unit potential and H-potential change as a function of muscle length.
authors.affiliation: Department of Exercise and Sport Sciences, University of Arizona, Tucson.
authors.forename: S J
authors.initials: SJ
authors.lastname: Garland
authors.forename: L
authors.initials: L
authors.lastname: Gerilovsky
authors.forename: R M
authors.initials: RM
authors.lastname: Enoka
mesh_terms: D000200:Action Potentials; D004594:Electrophysiology; D006181:H-Reflex; D006801:Humans; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction; D009132:Muscles / Q000033:anatomy & histology*; D013848:Thigh