title: Short latency stretch reflex in human lumbar paraspinal muscles.
abstract: The aim of the study was to measure stretch reflex latencies of the lumbar paraspinal muscles. An electromechanical tapping system was constructed enabling an accurate estimation of short latencies by utilizing a new technique combining results for different tapping durations. Latency parameters (onset, peak and zero-crossing of EMG signal) were obtained for the paraspinal muscles at the L3/L4 level for 10 male subjects. Detection of EMG onset, which was determined by a threshold criterion (2.5 S.D. of pre-activity), yielded 7.4+/-1.4 ms corresponding to a physiological short latency onset of 6.5 ms, which is considerably shorter than previously reported. However, it is shown to be consistent with the expected latency value for a monosynaptic stretch reflex for the paraspinal muscles of the low back.
authors.affiliation: Department of Physiology, National Institute of Occupational Health, Lersø Parkallé 105, DK-2100 Copenhagen, Denmark. js@ami.dk
authors.forename: Jørgen
authors.initials: J
authors.lastname: Skotte
authors.forename: Nis
authors.initials: N
authors.lastname: Hjortskov
authors.forename: Morten
authors.initials: M
authors.lastname: Essendrop
authors.forename: Bente
authors.initials: B
authors.lastname: Schibye
authors.forename: Niels
authors.initials: N
authors.lastname: Fallentin
mesh_terms: D000328:Adult; D004576:Electromyography; D006801:Humans; D008161:Lumbosacral Region / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods*; D011930:Reaction Time / Q000502:physiology*; D012026:Reflex, Stretch / Q000502:physiology*; D015203:Reproducibility of Results