Highlights • LFR group experienced a significantly higher rate of RF and BF muscle fatigue, compared to the MFR group. • Static WBV stimuli produced significant increases in lower-body muscular activation. • Highest EMG activity in the LFR group was recorded when the frequency and amplitude were 40 Hz and 4 mm, respectively. • The muscle activation of MFR group decreased by increasing frequency of the WBV. • Increasing the amplitude of WBV attains significant increases in the activation of LFR and MFR leg muscles significant. The purpose of this study was to determine the effects of static whole-body vibration (WBV) on the Electromyograhic (EMG) responses of leg muscles, which are fatigue-resistant in different manner. The study population was divided into two groups according to the values obtained by the Fatigue Index [Group I: Less Fatigue Resistant (LFR), n = 11; Group II: More Fatigue Resistant (MFR), n = 11]. The repeated electromyographic (EMG) activities of four leg muscles were analyzed the following determinants: (1) frequency (30 Hz, 35 Hz and 40 Hz); (2) stance position (static squat position); (3) amplitude (2 mm and 4 mm) and (4) knee flexion angle (120°), (5) vertical vibration platform. Vibration data were analyzed using Minitab 16 (Minitab Ltd, State College, PA, USA). The significance level was set at p < .05. The study results showed that static WBV stimuli given at different frequencies and amplitudes resulted in a significant increase (p < .05) in compared, the LFR group showed significantly (1) higher rates of quadriceps femoris and hamstring muscle fatigue (p < .05), (2) higher levels of knee extensor and flexor torque (p < .05) and (3) higher percentage increases in EMG activation at higher frequencies (max at 40 Hz) and amplitudes (4 mm) (p < .05). The present study can be used for the optimal prescription of vibration exercise and can serve to guide the development of training programs.
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