The effect of dynamic whole-body vibration warm-up on lower extremity performance

Objective. Numerous studies have postulated that whole-body vibration (WBV) exercise could be used as a warm-up procedure. Unfortunately, the inconsistency in reporting and standardizing the WBV protocols participate to the lack of consensus of the literature. The purpose of this study was, first, to investigate whether a WBV intervention performed on a vertical synchronous platform could be an effective warm-up procedure. Second, we meticulously paid attention to the quantification of the effective acceleration produced by the platform. Methods. Fourteen recreationally active individuals performed either a WBV (30 Hz/4 mm; theoretical acceleration of 71 m.s(-2)) or non-vibration (NWBV) intervention comprising dynamic squatting exercises intermittently (30 s/30 s) during ten minutes. Pre- and post-intervention tests consisted of countermovement jump, bilateral isometric maximal voluntary contraction of knee extensor muscles and sit and reach box test. Post-tests were performed at one and five minutes after the intervention. Results. Countermovement jump height (+4.92%; P<0.05) and lower extremity flexibility (+13.56%; P<0.001) were significantly increased at five minutes after the WBV intervention whereas no change was observed after the NWBV. Neither WBV nor NWBV intervention improved the bilateral isometric strength of the knee extensor muscles. Importantly, the effective vertical acceleration delivered by the platform was about half the theoretical one (i.e., 34.7 m.s(-2)). Conclusion. In the absence of change after the NWBV intervention, we concluded that our dynamic WBV exercise constitutes a successful warm-up procedure to improve lower extremity performance. The present results also emphasize that the effective acceleration of the WBV devices should be methodically monitored. (C) 2015 Elsevier Masson SAS. All rights reserved.