Table 2. Mean differences between conditions and confidence intervals for the Root Mean Square (RMS) of VL muscle in the 30 Hz and 50 Hz groups. Mean differences between conditions Confidence interval (CI 95%) 30 Hz group 50 Hz group No Vibration vs WBV with no Filter p No Vibration vs WBV with Filter p No Vibration vs WBV with no Filter p No Vibration vs WBV with Filter p RMS (%MVIC) 10.73 (3.92 to 17.53) .001 2.57 (0.75 to 4.39) .002 10.53 (4.68 to 16.39) .0001 3.55 (1.2 to 5.89) .001 MVIC: Maximal Voluntary Isometric Contraction; Hz: Hertz; RMS: Root Mean Square; SD: Standard deviation; WBV: Whole-body vibration