Resumen:
This study investigated the magnitude of whole-body vibration (WBV) at 30 Hz induced in surface electromyography root-mean-square (EMGrms) signals of different amplitudes and footwear conditions of unloaded isometric half squat (100). For this purpose, 10 healthy and active males (age 28.7 +/- 4.6 yr; height 180 +/- 5.9 cm; and weight 90 +/- 13.4 kg) volunteered to participate in this study. Subjects were exposed to the WBV treatment using a vibration platform (FreeMotion Fitness iTonic). The subjects were exposed randomly to 4 different treatments of WBV: with shoes 2 mm amplitude, without shoes 2 mm, with shoes 4 mm, and without shoes 4 mm. The EMGrms signals were recorded from the vastus lateralis and the gastrocnemius medialis muscle during the different conditions. The WBV treatments resulted in a significantly higher (p <or= 0.05) EMGrms compared with unloaded isometric half squat (without WBV). The WBV treatment that induced the highest EMGrms signals of the vastus lateralis was during the amplitude of 4 mm without shoes (+62.7%; p < 0.01), whereas 4 mm with shoes induced the highest EMGrms signals of the gastrocnemius medialis (+142.7%; p < 0.01). These data suggest that wearing shoes doe...