02250nas a2200169   4500000000100000008004100001653002400042653001200066100001600078700001600094700001400110245012900124300003500253490000700288050000600295520177900301       2006                            d10aPeer Reviewed Paper10aChecked1 aHerbert Rob1 aMcCarren B.1 aAlison J.00aManual vibration increases expiratory flow rate via increased intrapleural pressure in healthy adults: an experimental study  a267-271. [Impact Factor 1.870]0 v52  aN3 a<p>
QUESTION: What is the relationship between vibration of the chest wall and the resulting chest wall force, chest wall circumference,intrapleural pressure, and expiratory flow rate? Is the change in intrapleural pressure during vibration the sum of the intrapleural pressure due to recoil of the lung, chest wall compression, and chest wall oscillation? DESIGN: Randomised, within-subject,experimental study. PARTICIPANTS: Seven experienced cardiopulmonary physiotherapists and three healthy adults. INTERVENTION: Vibration (compression + oscillation), compression alone, and oscillation alone were applied manually to the chest walls of healthy participants during passive exertion and compared with passive expiration alone. Outcome measures: Chest wall force, chest wall circumference, intrapleural pressure, and expiratory flow rate. RESULTS: During vibration, coherence was high(r2 &gt; 0.97) between external chest wall force, chest wall circumference, intrapleural pressure, and expiratory flow. The mean change in intrapleural pressure during vibration was 9.55 cmH2O (SD 1.66), during chest compression alone was 8.06 cmH2O(SD 1.65), during oscillation alone was 7.93 cmH2O (SD 1.57), and during passive expiration alone was 6.82 cmH2O (SD 1.51).During vibration, compression contributed 13% of the change in intrapleural pressure, oscillation contributed 12%, and lung recoil contributed the remaining 75%. CONCLUSIONS: During vibration the chest behaves as a highly linear system. Changes in intrapleural pressure occurring during vibration appear to be the sum of changes in pressure due to lung recoil and the compressive and oscillatory components of the technique, which suggests that all three components are required to optimise expiratory flow.
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