title: Sudden loading perturbation to determine the reflex response of different back muscles: a reliability study.
abstract: In this study we estimate the reliability of reflex response variables to identify the main sources of variability and to estimate appropriate measurement strategies to obtain more reliable measures. Back muscle surface electromyography (EMG) was recorded in healthy males during anteriorly-directed sudden loading perturbations applied to the trunk. Measures of EMG reflex latency and amplitude were obtained. The generalizability theory was used as a framework to estimate the magnitude of the different variance components and the reliability of the measures corresponding to various simulations of different measurement strategies. Reliability of the different variables was poor to moderate (intraclass correlation coefficient range 0-0.62). Averaging scores across homologous muscles and several trials were strategies to achieve more acceptable reliability. The reflex response of back muscles is inherently variable, and a large measurement effort is necessary to obtain reliable and, consequently, valid and responsive estimations of this neuromuscular function.
authors.affiliation: Institut de recherche Robert-Sauvé en santé et sécurité du travail, Montréal, Québec, Canada.
authors.forename: Brenda R
authors.initials: BR
authors.lastname: Santos
authors.forename: Christian
authors.initials: C
authors.lastname: Larivière
authors.forename: Alain
authors.initials: A
authors.lastname: Delisle
authors.forename: David
authors.initials: D
authors.lastname: McFadden
authors.forename: André
authors.initials: A
authors.lastname: Plamondon
authors.forename: Daniel
authors.initials: D
authors.lastname: Imbeau
mesh_terms: D000328:Adult; D001415:Back / Q000502:physiology*; D004576:Electromyography / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D015203:Reproducibility of Results; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult