Moira Elizabeth Schöttler for their assistance in editing the manuscript. “
“The breathing patterns of patients with chronic obstructive pulmonary disease (COPD) are abnormal, especially in patients

with pulmonary hyperinflation (Aliverti et al., 2004 and McKenzie et al., 2009). Airflow obstructions and mechanical disadvantages of the diaphragm contribute to the changes in the breathing pattern and thoracoabdominal motion observed in these patients (Sackner et al., 1984 and Tobin et al., 1983). Most of these abnormalities suggest a malfunction of respiratory muscles, especially the diaphragm, with the use of sternocleidomastoid (SMM) and abdominal muscle (ABD) being enhanced (Decramer, 1997 and McKenzie et al., 2009).

These patients also exhibit other adaptations, such as modified chest wall and diaphragm shapes, which accommodate the increased volume and adaptations of Alisertib solubility dmso muscles fibers to preserve strength and increase endurance (Loring Baf-A1 purchase et al., 2009 and McKenzie et al., 2009). These abnormalities are associated with poor exercise tolerance, dyspnea and lower functional capacity (Loring et al., 2009). To reduce these consequences, the Joint American College of Chest Physicians/American Association of Cardiovascular and Pulmonary Rehabilitation recommend inspiratory muscle training (IMT) with inspiratory loaded breathing at least 30% of the maximal inspiratory pressure (MIP) (Lotters et al., 2002) as part of rehabilitation programs for patients with COPD (American Association of Cardiovascular and Pulmonary Rehabilitation, 1997). The benefits of IMT have been described by many authors and include increased strength and endurance of the inspiratory muscles, reduced dyspnea and fatigue, increased exercise tolerance and distance walked during the six minute walk test, improved performance in daily activities and an improved quality of life (Geddes et al., 2008, Gosselink et al., Farnesyltransferase 2011 and Shoemaker et al., 2009). Optoelectronic plethysmography (OEP) (Cala et al.,

1996) can be used to elucidate which chest wall (CW) compartment contributes the most to the tidal volume and breathing pattern in different situations. Recent reviews summarized the use of OEP in COPD patients (Parreira et al., 2012 and Romagnoli et al., 2008). Aliverti et al. (2004) found different behavior to increase the tidal volume during exercise: a decrease of end expiratory abdominal volume in euvolemics patients and an increase of end inspiratory abdominal and rib cage volume in hyperinflated patients. Bianchi et al. (2004) also identified during pursed-lip breathing an increased tidal volume associated with increasing end inspiratory rib cage volume and reducing end expiratory rib cage and abdominal volumes. Hostettler et al. (2011) assessed the effect of ILB and identified association between chest wall volume changes and respiratory muscle strength in 12 healthy subjects.