Alternative to traditional stretching methods for flexibility enhancement in well-trained combat athletes: local vibration versus whole-body vibration

This study aimed to compare the effect of local vibration (LV) and whole body vibration (WBV) on lower body flexibility and to assess whether vibration treatments were more effective than traditionally used static and dynamic stretching methods. Twenty-four well-trained male combat athletes (age: 22.7 ± 3.3 years) performed four exercise protocols – LV (30 Hz, 4 mm), WBV (30 Hz, 4 mm), static stretching (SS), and dynamic stretching (DS) – in four sessions of equal duration 48 hours apart in a randomized, balanced order. During a 15-minute recovery after each protocol, subjects performed the stand and reach test (S&R) at the 15th second and the 2nd, 4th, 6th, 8th, 10th and 15th minute. There was a similar change pattern in S&R scores across the 15-minute recovery after each protocol (p = 0.572), remaining significantly elevated throughout the recovery. A significant main protocol effect was found for absolute change in S&R scores relative to baseline (p = 0.015). These changes were statistically greater in LV than WBV and DS. Changes in SS were not significantly different from LV, but were consistently lower than LV with almost moderate effect sizes. After LV, a greater percentage of subjects increased flexibility above the minimum detectable change compared to other protocols. Subjects with high flexibility (n = 12) benefited more from LV compared with other methods (effect size ≥ 0.862). In conclusion, LV was an effective alternative exercise modality to acutely increase lower extremity flexibility for well-trained athletes compared with WBV and traditional stretching exercises. CITATION: Kurt C. Alternative to traditional stretching methods for flexibility enhancement in well-trained combat athletes: local vibration versus whole-body vibration. Biol Sport. 2015;32(3):225–233. Received: 2014-10-20; Reviewed: 2015-01-03; Re-submitted: 2015-01-04; Accepted: 2015-01-04; Published: 2015-04-23. In combat sports such as judo, tae kwon do, and karate, static stretching (SS) is predominantly used as part of the warm-up process. It is also used at the end of training sessions to improve and/or maintain flexibility. However, some research indicates that SS may have detrimental effects on explosive strength (i.e. vertical jump), maximum strength, speed, and agility if used before muscular activity including these biomotor abilities [4,5]. To overcome the negative effects of SS, it has been recommended to replace static stretching with dynamic stretching (DS) in the warm-up period. DS has no detrimental effects and may have positive effects on subsequent muscular activity [5,8]. On the other hand, DS is not as effective as SS at improving flexibility [5,8]. Whole body vibration (WBV) is another training modality used to enhance flexibility [1,9-13]. Since SS has detrimental effects on explosive activities and DS is less effective than SS at increasing flexibility, WBV may be a better alternative to these traditional stretching methods for enhancing acute flexibility prior to sporting activities. In WBV, a mechanical stimulus with an oscillatory motion is applied to the whole body via a vibrating platform. Frequency, amplitude, acceleration, and duration are the main variables constituting the Original Paper Biol. Sport 2015;32:225-233 DOI: 10.5604/20831862.1150305