Vibration and stretching effects on flexibility and explosive strength in young gymnasts.
OBJECTIVE
Effects of simultaneous vibration-stretching on flexibility and explosive strength in competitive female gymnasts were examined.


METHODS
Twenty-two female athletes (age = 11.3 +/- 2.6 yr; body mass = 35.3 +/- 11.6 kg; competitive levels = 3-9) composed the simultaneous vibration-stretching (VS) group, which performed both tests. Flexibility testing control groups were stretching-only (SF) (N = 7) and vibration-only (VF) (N = 8). Explosive strength-control groups were stretching-only (SES) (N = 8) and vibration-only (VES) (N = 7). Vibration (30 Hz, 2-mm displacement) was applied to four sites, four times for 10 s, with 5 s of rest in between. Right and left forward-split (RFS and LFS) flexibility was measured by the distance between the ground and the anterior suprailiac spine. A force plate (sampling rate, 1000 Hz) recorded countermovement and static jump characteristics. Explosive strength variables included flight time, jump height, peak force, instantaneous forces, and rates of force development. Data were analyzed using Bonferroni adjusted paired t-tests.


RESULTS
VS had statistically increased flexibility (P) and large effect sizes (d) in both the RFS (P = 1.28 x 10(-7), d = 0.67) and LFS (P = 2.35 x 10(-7), d = 0.72). VS had statistically different results of favored (FL) (P = 4.67 x 10(-8), d= 0.78) and nonfavored (NFL) (P = 7.97 x 10(-10), d = 0.65) legs. VF resulted in statistical increases in flexibility and medium d on RFS (P = 6.98 x 10(-3), d = 0.25) and statistically increased flexibility on VF NFL flexibility (P = 0.002, d = 0.31). SF had no statistical difference between measures and small d. For explosive strength, there were no statistical differences in variables in the VS, SES, and VES for the pre- versus posttreatment tests.


CONCLUSIONS
Simultaneous vibration and stretching may greatly increase flexibility while not altering explosive strength.
Kinser
Ann M
AM
Sports Performance Enhancement Consortium, Kinesiology, Leisure, and Sports Science, East Tennessee State University, Johnson City, TN, USA.
Ramsey
Michael W
MW
O'Bryant
Harold S
HS
Ayres
Christopher A
CA
Sands
William A
WA
Stone
Michael H
MH
D000886:Anthropometry; D001823:Body Composition / Q000502:physiology; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006173:Gymnastics / Q000502:physiology*; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D052580:Muscle Stretching Exercises; D018482:Muscle, Skeletal / Q000502:physiology*; D018583:Pliability; D016059:Range of Motion, Articular; D013997:Time Factors; D014732:Vibration