title: Effect of Achilles tendon vibration on posture in children.
abstract: This study investigated the effect of unilateral Achilles tendon vibration on postural response in children and young adults during standing. Thirty healthy subjects participated in this study including ten 6-year-old children (YC group), ten 10-year-old children (OC group), and ten young adults (YA group). Eight-second vibration was elicited in each trial from a small vibrator attached above the right Achilles tendon when participants stood barefoot on a force platform. Three 40-s trials were collected under both eyes-open and eyes-closed conditions. Center of pressure (COP) was calculated to examine postural response during the pre-vibration, vibration and post-vibration phases. Results show that both the YC and OC groups had a greater COP average velocity than the YA group in all three phases. Tendon vibration induced a directionally specific postural response in all three groups such that the onset of vibration induced a posterior and medial COP shift during the vibration phase, and the offset of vibration induced an anterior and lateral COP shift during the post-vibration phase. Timing of the maximal COP shift was comparable among three groups in both anterior-posterior (AP) and medial-lateral (ML) directions. However, only the OC group showed an adult-like magnitude of the maximal COP shift during the post-vibration phase in the AP direction. These results suggest that 6-year-old children may start showing an adult-like directionally specific response and temporal parameter to tendon vibration during standing; however, the development of an adult-like spatial postural response to tendon vibration may take more than 10 years.
authors.affiliation: Centre for Studies in Aging, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: McKay
authors.affiliation: Department of Kinesiology and Health, Georgia State University, Atlanta, GA, USA. Electronic address: jwu11@gsu.edu.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wu
authors.affiliation: Center for Human Growth and Development, University of Michigan, Ann Arbor, MI, USA; INEFC, Department of Health and Applied Sciences, University of Barcelona, Barcelona, Spain.
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Angulo-Barroso
mesh_terms: D000125:Achilles Tendon / Q000502:physiology*; D000704:Analysis of Variance; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D010808:Physical Examination; D004856:Postural Balance / Q000502:physiology*; D011312:Pressure; D011434:Proprioception / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D014732:Vibration
keywords: Achilles tendon vibration; Center of pressure; Children; Posture