Diaphragmatic mobility: relationship with lung function, respiratory muscle strength, dyspnea, and physical activity in daily life in patients with COPD

OBJECTIVE: To evaluate diaphragmatic mobility in relation to lung function, respiratory muscle strength, dyspnea, and physical activity in daily life (PADL) in patients with COPD. METHODS: We included 25 patients with COPD, classified according to the Global Initiative for Chronic Obstructive Lung Disease criteria, and 25 healthy individuals. For all of the participants, the following were evaluated: anthropometric variables, spirometric parameters, respiratory muscle strength, diaphragmatic mobility (by X-ray), PADL, and the perception of dyspnea. RESULTS: In the COPD group, diaphragmatic mobility was found to correlate with lung function variables, inspiratory muscle strength, and the perception of dyspnea, whereas it did not correlate with expiratory muscle strength or PADL. CONCLUSIONS: In patients with COPD, diaphragmatic mobility seems to be associated with airway obstruction and lung hyperinflation, as well as with ventilatory capacity and the perception of dyspnea, although not with PADL.