title: The effects of whole body vibration on EMG activity of the upper extremity muscles in static modified push up position.
abstract: BACKGROUND
  Whole Body Vibration (WBV) has been reported to change neuromuscular activity which indirectly assessed by electromyography (EMG). Although researches regarding the influence of WBV on EMG activity of the upper extremity muscles are in their infancy, contradictory findings have been reported as a result of dissimilar protocols.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the effects of WBV on electromyography (EMG) activity of upper extremity muscles in static modified push up position.
  
  
  METHODS
  Forty recreationally active females were randomly assigned in WBV and control groups. Participants in WBV group received 5 sets of 30 seconds vibration at 5 mm (peak to peak) and 30 Hz by using vibratory platform. No vibration stimulus was used in the control group. Surface EMG was recorded from Upper Trapezius (UT), Serratus Anterior (SA), Biceps Brachii (BB) and Triceps Brachii (TB) muscles before, during and after the vibration protocol while the subjects maintained the static modified push up position. EMG signals were expressed as root mean square (EMGrms) and normalized by maximum voluntary exertion (MVE).
  
  
  RESULTS
  EMGrms activity of the studied muscles increased significantly during the vibration protocol in the WBV group comparing to the control group (P ≤ 0.05). The results indicated that vibration stimulus transmitting via hands increased muscle activity of UT, SA, BB and TB muscles by an average of 206%, 60%, 106% and 120%, respectively, comparing to pre vibration values.
  
  
  CONCLUSIONS
  These findings suggest that short exposure to the WBV could increase the EMGrms activity of the upper extremity muscles in the static modified push-up position. However, more sessions of WBV application require for a proper judgment.
authors.forename: Zinat
authors.initials: Z
authors.lastname: Ashnagar
authors.forename: Azadeh
authors.initials: A
authors.lastname: Shadmehr
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Hadian
authors.forename: Saeed
authors.initials: S
authors.lastname: Talebian
authors.forename: Shohreh
authors.initials: S
authors.lastname: Jalaei
mesh_terms: D000328:Adult; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D034941:Upper Extremity / Q000502:physiology; D014732:Vibration; D055815:Young Adult
keywords: Electromyography; modified push up; upper limb muscles; whole body vibration