[A quantitative study on the effect of breathing exercises in improving respiratory muscle contration].

To study quantitatively the effect of breathing exercises on the prevention of progression in chronic obstructive pulmonary disease (COPD), 324 patients with stable COPD were randomly assigned to either breathing exercises (BE) or placebo medicine as control. The maximum respiratory pressure (320 cases) and transdiaphragmatic pressure (129 cases) were monitored with RMS-1 and Type-2 gastrointestinal pressure measuring instrument. BE were taught and checked by experienced specialists periodically. Patients in BE group were compared with those in the control group by measuring MIP, MEP, Pdi, and Pdimax after one to 20 months. In BE group MIP increased by 30.42%, MEP 32.10%, Pdi 30.94%, and Pdimax 65.59% (P < 0.001). No significant change was observed in the control group. MIP, MEP, Pdi, and Pdimax increased by 6.95%, 2.92%, 14.63% and 9.05% respectively (P < 0.05) in the control group. It is shown preliminarily that BE had potent and lasting effect on respiratory muscle contraction after studying large number of cases. The methods mentioned above can be used as quantitative indices for the contractile properties of respiratory muscle.