Impact of whole body vibration training on balance and muscle power in patients with severe COPD – A randomized, controlled trial

Background: There are several studies that have shown that whole body vibration training (WBVT) is able to improve exercise capacity in patients with COPD. However, the underlying mechanisms remain unknown. Objective: To evaluate the effect of WBVT on balance and muscle power in patients with severe COPD. Methods: Fifty patients (age: 63±7 ys, FEV 1 : 35±10 %pred.) were recruited during a 3-week inpatient pulmonary rehabilitation program (PR). On top of conventional endurance and strength training patients performed dynamic squat training sessions (4x2min, 3x/wk) randomized into a WBVT-group performing squat training on a vibration platform or a control group (CON) exercising on the floor. To assess balance patients were asked to stand still for 10 sec in different static positions (Romberg stand, tandem stand, 1-leg stand with open and closed eyes). Muscle power tests consisted of 2-leg jumps, 5-repetition sit-to-stand test (STST) as well as the 1-min STST. All tests were performed on a force measurement platform pre and post PR. Results: After PR the WBVT-group could improve balance significantly more in 2 out of 4 domains compared to the CON-group (tandem stand: WBVT +10% vs. CON -14%, p=0.008 and 1-leg stand: WBVT +6% vs. CON -9%). Also some measures of muscle power like jump height (WBVT: +26% vs. CON: +1%, p=0.010) and the 5-STST (WBVT: -5.2±5.1sec vs. CON: -2.4±0.9sec) improved significantly more in the WBVT-group. Conclusion: This is the first study that investigated potential mechanisms of the beneficial effect of WBVT. It was found that neuromuscular adaptations like improvements in balance and muscle power may explain some of these positive effects.