Acute Effects of Whole-Body Vibration on Lower Body Flexibility and Strength

Whole-body vibration (WBV) is a neuromuscular training method designed to improve muscle strength and mobility that has become an increasing popular mode of alternative training in European athletes. Purpose: The purpose of this study was to examine the acute effects of WBV training on flexibility, heart rate, and peak isokinetic torque. Methods: Twenty healthy adults (12 males, 8 females), untrained to WBV, participated in this study. All participants stood upright on a vibration platform for a total of 6 minutes. Vibration frequency was gradually increased during the first minute to a frequency of 26 Hz, which was maintained for the remaining five minutes. Immediately prior to and following the 6 min of WBV, the subjects participated in assessments of heart rate, low back and hip-joint flexibility and isokinetic torque. Heart rate was measured using a portable heart rate monitor. Low back and hip-joint flexibility was determined using a sit-and-reach box test. Peak isokinetic torque of knee extension and flexion were measured by means of a motor driven dynamometer with velocity fixed at 120 degrees/sec. Pre- and post comparisons were made using Students paired t-tests. Results: Analyses revealed significant increases in flexibility (31.9 ± 7.9 vs. 27.3 ± 8.5cm, p<0.05) and in heart rate response (93.8 ± 11.8 vs. 78.8 ± 11.0bpm, p<0.05) following WBV. Peak torque of knee extension increased significantly (167.7 ± 39.7 vs. 158.9 ± 34.0 Nm, p<0.05) as did peak torque of knee flexion (92.1 ± 27.2 vs. 85.4 ± 23.9 Nm, p<0.05). The average torque of knee extension and knee flexion significantly increased (56.5 ± 11.4 vs. 52.8 ± 11.7 Nm and 39.5 ± 11.6 vs. 35.4 ± 9.5 Nm, respectively, p<0.05). Conclusion: The findings of this preliminary study suggests WBV training may elicit acute improvements in flexibility, heart rate and peak isokinetic torque