The effect of positioning and diaphragmatic breathing exercises on respiratory muscle activity in people with chronic obstructive pulmonary disease.

BACKGROUND

Body positioning and diaphragmatic breathing may alter respiratory pattern and reduce dyspnoea in people with chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine the effect of positioning and diaphragmatic breathing on respiratory muscle activity in a convenience sample of people with COPD, using surface electromyography (sEMG).

METHODS

This prospective descriptive study recorded sEMG measurements at baseline, after upright positioning, during diaphragmatic breathing and 5 minutes thereafter. Vital signs and levels of perceived dyspnoea were recorded at baseline and at the end of the study. Data were analysed using repeated measures ANOVAs with post hoc -tests for dependent and independent variables.

RESULTS

Eighteen participants (13 male; mean ± standard deviation age 59.0 ± 7.9 years) were enrolled. Total diaphragmatic activity did not change with repositioning ( = 0.2), but activity increased from 7.3 ± 4.2 µV at baseline to 10.0 ± 3.3 µV during diaphragmatic breathing ( = 0.006) with a subsequent reduction from baseline to 6.1 ± 3.5 µV ( = 0.007) at the final measurement. There was no change in intercostal muscle activity at different time points ( = 0.8). No adverse events occurred. Nutritional status significantly affected diaphragmatic activity ( = 0.004), with participants with normal body mass index (BMI) showing the greatest response to both positioning and diaphragmatic breathing. There were no significant changes in vital signs, except for a reduction in systolic/diastolic blood pressure from 139.6 ± 18.7/80.4 ± 13.0 to 126.0 ± 15.1/75.2 ± 14.7 ( < 0.05).

CONCLUSION

A single session of diaphragmatic breathing transiently improved diaphragmatic muscle activity, with no associated reduction in dyspnoea.