title: Test-retest reliability of muscle vibration effects on postural sway.
abstract: The effect of alterations in the processing of proprioceptive signals, on postural control, has been studied using muscle vibration effects. However, reliability and agreement of muscle vibration have still to be addressed. This study aimed to assess intra- and interday reliability and agreement of vibration effects of lumbar paraspinal and triceps surae muscles in a non-selected sample of 20 subjects, standing on solid surface and on foam. We used mean position and velocity of Centre of Pressure (CoP), during and after vibration to quantify the effect of muscle vibration. We also calculated the ratio of vibration effects on the lumbar paraspinal and triceps surae muscles (proprioceptive weighting). Displacement of the CoP during vibration showed good reliability (ICCs>0.6), and proprioceptive weighting of displacement fair to good reliability (0.52-0.73). Agreement measures were poor, with most CV's ranging between 18% and 36%. Change in CoP velocity appeared not to be reliable. Balance recovery, when based on CoP position and calculated a short period after cessation of vibration, showed good reliability. According to this study, displacement during vibration, proprioceptive weighting and selected recovery variables are the most reliable indicators of the response to muscle vibration.
authors.affiliation: Research Group Lifestyle and Health, Faculty of Health Care, University of Applied Sciences, Utrecht, The Netherlands. Electronic address: henri.kiers@hu.nl.
authors.forename: Henri
authors.initials: H
authors.lastname: Kiers
authors.affiliation: Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium. Electronic address: simon.bramagne@faber.kuleuven.be.
authors.forename: Simon
authors.initials: S
authors.lastname: Brumagne
authors.affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University, Amsterdam, The Netherlands. Electronic address: j.vandieen@fbw.vu.nl.
authors.forename: Jaap
authors.initials: J
authors.lastname: van Dieën
authors.affiliation: Research Group Lifestyle and Health, Faculty of Health Care, University of Applied Sciences, Utrecht, The Netherlands; Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium. Electronic address: luc.Vanhees@faber.kuleuven.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Vanhees
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D015233:Models, Statistical; D018482:Muscle, Skeletal / Q000502:physiology*; D026741:Physical Therapy Modalities; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology; D011434:Proprioception / Q000502:physiology*; D015203:Reproducibility of Results; D014732:Vibration
keywords: Muscle vibration; Postural control; Proprioception; Reliability