Whole-body vibration training improves the balance ability and leg strength of athletic throwers

BACKGROUND: Physical strength improvements have been observed with whole-body vibration training (WBVT); however, the appropriate load and duration have not been determined. Furthermore, studies on WBVT in throwing athletes, for whom power training is important, are lacking. Therefore, we examined the effectiveness of lower limb training by WBVT in male throwing athletes. METHODS: Fourteen male throwing athletes were enrolled. Lower limbs training (squat, single-leg squat, forward lunge, and side lunge) was performed with WBVT (N.=7) or without WBVT (N.=7). Training was conducted three times a week for a total of eight weeks (four weeks at 30 Hz for 40 s, then four weeks at 50 Hz for 60 s for the WBVT group). Jump performance, lower limb muscular strength, and balancing ability were assessed before, at the mid-point, and after training. RESULTS: Significant improvement in the vertical jump was only observed in the WBVT group (pre-vs. post-training: P<0.05; pre-vs. mid-training: P<0.01). In the WBVT group, significant improvements were observed in 26 out of 32 balancing ability assessments. In contrast, only two such assessments significantly improved in the Control group. In the WBVT group, a significant improvement of 5% was observed in left and right extension for the knee joint isokinetic muscle force test with an angular velocity of 60 degrees/s. CONCLUSIONS: These results suggest that lower limb training with WBVT improves leg muscle strength and balancing ability in athletic throwers. In particular, dynamic balancing ability is increased, with significant improvement in the left and right legs.