Acute effects of whole-body vibration on trunk muscles in young healthy adults.

Little is known about the impact of whole body vibration (WBV) training on trunk muscles. Thus, this study investigated the acute effects of WBV on back and abdominal muscle activity. Twenty-five healthy subjects (24.7 ± 3.0 years, 17 men) conducted eight common static exercises for the back and abdominal muscles in a random order on a vibration platform, with and without vibration. Surface EMG was measured from back and abdominal muscles. Vibration-induced motion artefacts were removed from the EMG signal. Muscle activity with and without vibration was normalized to maximal voluntary contraction (MVC) and compared. The addition of vibration resulted in significant increases in muscle activity particularly in the exercises for the abdominal muscles of up to 7.2 ± 5.5% MVC (median ± semi-interquartile range). In the back muscles, the largest difference by adding vibration was 1.6 ± 1.4% MVC (median ± semi-interquartile range). The results of this study indicate a low to moderate increase in trunk muscle activation due to WBV. Presumably, this effect might depend on the distance from the corresponding muscle to the vibration platform and on how much the exercise position challenges body balance. However, the relevance of these findings has to be further investigated in training studies.