Application of acute whole-body vibration and lower-body exercise: Effects on concentric torque in lower-limb muscles

Study aim: With contrary evidence regarding the effectiveness of acute whole-body vibration training (WBVT) on sporting performance, the current study examined WBVT's effect on concentric torque of the quadriceps (Q) and hamstrings (H).

Material and methods: Following ethical approval, 11 male team sport players (age: 22.9 ± 3.3 yrs, height: 1.80 ± 0.07 m, mass: 82.5 ± 12.6 kg) completed three separate weekly WBVT sessions. Baseline and post-WBVT intervention measurements of Q and H concentric torque were recorded, using an isokinetic dynamometer, at each session. Isokinetic knee extension and flexion was performed at 180os-1 through 90o range of motion. For the training intervention, vibration amplitude remained at 2 mm, while frequency was set at 0Hz, 30Hz or 50 Hz; randomised so participants experienced one frequency per session. Torque data (Nm) and H and Q ratio (H: Q) were analysed using 3-way and 2-way ANOVA with repeated measures respectively, with three within subjects' factors: Frequency, muscle group and intervention.

Results: Main interaction effect (frequency x muscle group x intervention) was insignificant (P = 0.327). Significant muscle group x frequency (P = 0.029) and muscle group x intervention (P = 0.001) interactions were found. Intervention, regardless of WBVT, significantly increased concentric torque of H (P = 0.003) and significantly reduced concentric torque of Q (P = 0.031). While H: Q x frequency interaction was insignificant (P = 0.262), the intervention significantly improved H: Q (P = 0.001).

Conclusions: Team sport athletes experience a muscle-specific response in peak concentric torque to lower-body exercise. Acute WBVT does not provide additional positive or negative effects on Q or H strength.