Affiliations: Physical Therapy Department, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran
Correspondence:
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Corresponding author: Azadeh Shadmehr, Deputy for Research Affairs, Physical Therapy Department, School of Rehabilitation, Tehran University of Medical Sciences, Pich-e-Shemiran, Tehran, Iran. E-mail:shadmehr@tums.ac.ir
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.
Keywords: Electromyography, whole body vibration, upper limb muscles, modified push up
