Whole-body vibration training versus conventional balance training in patients with severe COPD-a randomized, controlled trial

Background: Whole-body vibration training (WBV) performed on a vibration platform can significantly improve physical performance in patients with chronic obstructive pulmonary disease. It has been suggested that an important mechanism of this improvement is based on an improvement in balance. Therefore, the aim of this study was to investigate the effects of WBV compared to conventional balance training. Methods: 48 patients with severe COPD (FEV1 : 37 +/- 7%predicted) and low exercise performance (6 min walk distance (6MWD): 55 +/- 10%predicted) were included in this randomized controlled trial during a 3 week inpatient pulmonary rehabilitation. All patients completed a standardized endurance and strength training program. Additionally, patients performed 4 different balance exercises 3x/week for 2 sets of 1 min each, either on a vibration platform (Galileo) at varying frequencies (5-26 Hz) (WBV) or on a conventional balance board (BAL). The primary outcome parameter was the change in balance performance during a semi tandem stance with closed eyes assessed on a force measurement platform. Muscular power during a countermovement jump, the 6MWD, and 4 m gait speed test (4MGST) were secondary outcomes. Non-parametric tests were used for statistical analyses. Results: Static balance performance improved significantly more (p = 0.032) in favor of WBV (path length during semi-tandem stand: - 168 +/- 231 mm vs.+ 1 +/- 234 mm). Muscular power also increased significantly more (p = 0.001) in the WBV group (+2.3 +/- 2.5 W/kg vs. - 0.1 +/- 2.0 W/kg). 6MWD improved to a similar extent in both groups (WBV: 48 +/- 46 m, p < 0.001 vs. BAL: 38+32 m; p < 0.001) whereas the 4MGST increased significantly only in the WBV-group (0.08 +/- 0.14 m/s(2), p = 0.018 vs. 0.01 +/- 0.11 m/s(2), p = 0.71). Conclusions: WBV can improve balance performance and muscular power significantly more compared to conventional balance training.