Effect of Whole-Body-Vibration Training on Trunk-Muscle Strength and Physical Performance in Healthy Adults: Preliminary Results of a Randomized Controlled Trial.

ABSTRACT

CONTEXT Whole-body-vibration (WBV) stimulus equipment has been used as a new training method for health promotion. Its use in the clinic has expanded to the field of sports and rehabilitation for disabled patients. WBV training is rapidly gaining popularity in health and fitness centers as an alternative method for improving muscle performance. Acute positive effects of WBV have been shown on lower-extremity muscle power and vertical-jump ability; however, there have not been any studies focusing on the long-term effects of WBV for trunk muscle and dynamic balance. OBJECTIVE: To investigate the effects of an 8-wk program of WBV in combination with trunk-muscle training on muscle performance in healthy, untrained adults. DESIGN: Laboratory-based, repeated-measures study. SETTING: University laboratory. PARTICIPANTS: 20 healthy university men. INTERVENTION Participants were randomly assigned to a WBV or non-WBV group. The WBV group performed a trunk-muscle-training program in combination with WBV; the non-WBV group performed the same muscle-training program without WBV for 8 wk. MAIN OUTCOME MEASURES: In the pre- and posttraining period, the participants were evaluated using the Functional Movement Screen (FMS), Y Balance Test (Y-test) (anterior, posteromedial, and posterolateral reach), trunk-muscle isometric strength (flexor, extensor, and flexorextensor ratio), squat jump, and countermovement jump. RESULTS: The WBV group had greater improvement than the non-WBV group in both trunk-flexor muscle strength (P = .02) and the Y-test (anterior reach) (P = .004) between pre- and posttraining. CONCLUSION: Adding WBV to a trunk-muscle-strengthening program may improve trunk-flexor isometric strength and anterior reach during the Y-test more than training without WBV. The WBV protocol used in this study had no significant impact on FMS scores, squat jumping, countermovement jumping, trunk-extensor isometric strength, or trunk flexorextensor ratio.