Abstract : The purpose of this study was to identify the influence of different magnitudes and directions of the vibration platform acceleration on surface electromyography (sEMG) during whole-body vibration (WBV) exercises. Therefore, a WBV platform was used that delivers vertical vibrations via a side-alternating mode, horizontal vibrations via a circular mode, and vibrations in all three planes via a dual mode. sEMG signals of selected lower limb muscles were measured in thirty individuals while they performed a static squat on a vibration platform. The WBV trials included two side-alternating trials (Side-L: 6 Hz, 2.5 mm; Side-H: 16 Hz, 4 mm), two circular trials (Circ-L: 14 Hz, 0.8 mm; Circ-H: 43 Hz, 0.8 mm), and four dual mode trials that were the combinations of the single mode trials (Side-L/Circ-L, Side-L/Circ-H, Side-H/Circ-L, Side-H/Circ-H). Further, control trials without vibration were assessed, and 3D platform acceleration was quantified during the vibration. Significant increases in the root mean square of the sEMG (sEMGRMS) compared to the control trial were found in most muscles for Side-L/Circ-H (+17 to +63%, P < 0.05), Side-H/Circ-L (+7 to +227%, P < 0.05), and Side-H/Circ-H (+21 to +207%, P < 0.01), and in the lower leg muscles for Side-H (+35 to + 138%, P < 0.05). Further, only the vertical platform acceleration showed a linear relationship (r = 0.970, P < 0.001) with the averaged sEMGRMS of the lower limb muscles. Significant increases in sEMGRMS were found with a vertical acceleration threshold of 18 m.s and higher. The present results emphasize that WBV exercises should be performed on a platform that induces vertical accelerations of 18 m.s and higher.