title: Effects of Local Muscle Vibration on the Displacement of Center of Pressure during Quiet Standing.
abstract: [Purpose] The purpose of this study was to investigate the effect of local vibration stimuli on body balance (trace area, trace length, and velocity) in healthy adults during double-leg standing. [Subjects and Methods] Thirty-nine subjects (10 male, 29 female) participated in this study. They were asked to keep their balance while holding four positions: standing with their eyes open, with and without vibration stimuli, and standing with their eyes closed, with and without vibration stimuli. The vibration stimuli, which had a duration of 30 sec, and a frequency of 60-80 Hz, were applied to the tibialis anterior and gastrocnemius muscle belly during double-leg standing. Balance measurement was performed using the Balance Trainer 4 (HUR Labs Oy, Tampere, Finland). All subjects provided informed consent prior to participation in this study. [Results] In the open-eyes position, there were no significant differences in trace area, trace length, and velocity of the center of pressure (COP) either with or without vibration stimuli. However, in the closed-eyes position, the vibration stimuli significantly decreased trace area, trace length, and velocity of the COP compared with when no vibration stimuli were applied. [Conclusion] These results suggest that vibration stimuli applied to the lower leg improve balance when a person's eyes are closed during double-leg quiet standing.
authors.affiliation: Department of Physical Therapy, College of Science, Kyungsung University, Republic of Korea.
authors.forename: Jin Tae
authors.initials: JT
authors.lastname: Han
authors.affiliation: Department of Physical Therapy, College of Science, Kyungsung University, Republic of Korea.
authors.forename: Myoung Hee
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Lee Keun Hee's Pediatric Development Research Institute, Republic of Korea.
authors.forename: Keun Hee
authors.initials: KH
authors.lastname: Lee
keywords: Center of pressure; Quiet standing; Vibration