JOURNAL OF SPORTS SCIENCE & MEDICINE
COMPARING THE EFFECTS OF VARIOUS WHOLE-BODY VIBRATION ACCELERATIONS ON COUNTER-MOVEMENT JUMP PERFORMANCE
David M. Bazett-Jones, Holmes W. Finch and Eric L. Dugan
Biomechanics Laboratory, Ball State University, Muncie, IN, USA.
|While it seems that whole body vibration (WBV) might be an effective
modality to enhance physical performance, the proper prescription of WBV
for performance enhancement remains unknown. The purpose of this study was
to compare the immediate effect of various WBV accelerations on counter
movement jump (CMJ) height, the duration of any effect, and differences
between men and women. Forty-four participants (33 men, 11 women) participated
in no less than four CMJ familiarization sessions and completed all vibration
sessions. Participants performed a pre-test (three maximal CMJs), followed
randomly by one of five WBV accelerations; 1g (no-WBV control), 2.16g, 2.80g,
4.87g, and 5.83g. Participants performed three maximal CMJs immediately,
five, and 10 minutes following each 45 sec WBV session. The mean of the
three performances was used and calculated as a percentage of the pre-vibration
mean value. A Repeated Measures Analysis of Variance (ANOVA; acceleration
x time x gender) model was used to analyze the data. The two-way interactions
of acceleration-gender (p = 0.033) and time-gender (p = 0.050) were significant.
Women performed significantly better following the 2.80g (p = 0.0064) and
5.83g (p = 0. 0125) WBV sessions compared to the 1g (control) session. Men,
however, did not experience performance enhancing effects following any
of the vibration sessions. While significant differences did not occur between
time in either gender, the effects of the 45 sec WBV session in women were
transient, lasting approximately five minutes. During the prescription of
WBV, gender should be considered given that the results of this study seem
to indicate that men and women respond differently to WBV. The results of
this study suggest that WBV might be a useful modality as applied during
the pre-competition warm-up.
Key words: Vertical jump, frequency, amplitude, gender.
Whole-body vibration (WBV), at low frequencies and low amplitudes,
has been reported to be a safe and effective method to improve athletic
performance (Cardinale and Bosco, 2003;
Cardinale and Wakeling, 2005).
Specifically, exposure to WBV has been shown to increase performance in
the vertical jump (Bosco et al., 2000;
Cardinale and Lim, 2003a;
Cochrane and Stannard, 2005;
Cormie et al., 2006;
Torvinen et al., 2002a).
However, it appears that the effects of WBV exposure on performance might
be dependent on characteristics (amplitude, frequency, acceleration magnitude)
of the exposure (Luo et al., 2005).
The combination of the amplitude and frequency determines the acceleration
magnitude of vibration (Cardinale and Bosco, 2003;
Luo et al., 2005),
measured in gs, where one g is the acceleration due to gravity (1g = 9.81
m·s-2). Since most WBV platforms allow for multiple settings
of amplitude and frequency, there are many possible combinations and resulting
accelerations. In addition, vibration training protocols (duration, volume,
and rest time) also differ in the literature, ranging from a single, 30
sec WBV exposure (Cormie et al., 2006)
to 10 minutes of WBV spaced over 16 minutes (Bosco et al., 2000).
Lastly, few studies (Torvinen et al., 2002a;
have compared the immediate effects of WBV on men versus women to examine
gender differences, reporting no differences between gender. The variety
of different training and experimental protocols found in the literature
makes it difficult to determine the optimal WBV acceleration and the mechanisms
leading to enhanced performance.
The three-way interaction was not significant (p = 0.522, ω2= 0.17). A significant two-way interaction was found for time X gender (p = 0.05, ω2= 0.14) and acceleration X gender (p = 0.033, ω2= 0.23) but not for acceleration X time (p = 0.204, ω2= 0.25). Percentage data is presented for these two-way interactions in Figures 2 and 3, respectively, and means and standard deviations are presented for these interactions in Tables 2 and 3. Pairwise analyses using Scheffe's correction demonstrated significant increases in the 2.80g (p = 0.0064) and 5.83g (p = 0.0125) accelerations compared to the 1g (control) acceleration for women. Significant differences were not found between any of the accelerations for men. Similarly, the Pairwise comparisons for time within each gender did not demonstrate any significant differences.
of this study demonstrate that a short WBV exposure
can increase CMJ performance. This enhancement was not seen in men, however,
in women the 2.80g and 5.83g WBV accelerations showed significant increases
of 9.0% and 8.3 %, respectively, over the control session. Our original
hypothesis that increases in WBV accelerations would lead to subsequent
(i.e. linear) performance improvements was not supported. It seems that,
in the current study, accelerations mattered less than the vibration frequency
since the 40 Hz (2.80g, 2-4 mm) and 50 Hz (5.83g; 4-6 mm) vibration sessions
demonstrated the greatest performance enhancements. The 30 Hz (1.81g,
2-4mm) and 35 Hz (4.87g, 4-6 mm) vibration sessions did not elicit changes
in performance, regardless of acceleration or amplitude. This study does
not confirm or deny that the frequency of vibration is the most important
|One 45 sec bout of WBV at 2.80g (40 Hz, 2-4 mm) and 5.83g (50 Hz, 4-6 mm) seems to be effective stimuli to elicit an improvement in CMJ performance in untrained women. In addition, the performance enhancing effects are transient in nature, lasting at least five minutes but less than ten minutes following exposure. These effects were not seen in men as all accelerations produced a reduction in performance. During the prescription of WBV, gender should be considered given that the results of this study seem to indicate that men and women respond differently to WBV. The results of this study suggest that WBV might be a useful modality as applied during the pre-competition warm-up.|
|The authors would like to thank Drs. Bruce Craig and Stacy Walker for their assistance with editing this manuscript. The vibration platform was provided by Power Plate North America, Inc. However, the authors have no conflicts of interest to report.|
David M. BAZETT-JONES
Employment: PhD Student, College of Health Sciences, Neuromechanics Laboratory, University of Wisconsin - Milwaukee.
Research interests: Rehabilitation biomechanics and outcomes, injury biomechanics and prevention, whole body vibration health and performance interventions, whole body vibration mechanisms.
W. Holmes FINCH
Employment: Assistant Professor, Department of Education Psychology, Ball State University.
Research interests: Multivariate statistical analysis, structural equation modeling.
Eric L. DUGAN
Employment: Assistant Professor of Exercise Science, School of Physical Education, Sport, and Exercise Science, Ball State University.
Research interests: Functional outcomes following clinical interventions; the influence of exercise protocols on health and performance; jumping/landing biomechanics.