Effects of breathing maneuver and sitting posture on muscle activity in inspiratory accessory muscles in patients with chronic obstructive pulmonary disease

Abstract

Background: To determine the influence of breathing maneuver and sitting posture on tidal volume (TV), respiratory rate (RR), and muscle activity of the inspiratory accessory muscles in patients with chronic obstructive pulmonary disease (COPD). Methods: Twelve men with COPD participated in the study. Inductive respiratory plethysmography and surface electromyography were used to simultaneously measure TV, RR, and muscle activity of the inspiratory accessory muscles [the scalenus (SM), sternocleidomastoid (SCM), and pectoralis major (PM) muscles] during quiet natural breathing (QB) and pursed-lips breathing (PLB) in three sitting postures: neutral position (NP), with armm support (WAS), and with arm and head support (WAHS). Results: Two-way repeated-measures analysis of variance was employed. In a comparison of breathing patterns, PLB significantly increased TV and decreased RR compared to QB. Muscle activity in the SM and SCM increased significantly in PLB compared to QB. In a comparison of sitting postures, the muscle activity of the SM, SCM, and PM increased in the forward-leaning position. Conclusions: The results suggest that in COPD, PLB induced a favorable breathing pattern (increased TV and reduced RR) compared to QB. Additionally, WAS and WAHS positions increased muscle activity of the inspiratory accessory muscles during inspiration versus NP. Differential involvement of accessory respiratory muscles can be readily studied in COPD patients, allowing monitoring of respiratory load during pulmonary rehabilitation.

Effect of pursed-lip breathing and forward trunk lean positions on regional chest wall volume and ventilatory pattern in older adults

“…To our knowledge, this study is the first to identify the effect of breathing patterns and body positions on both total and regional lung volumes in older adults. Overall, the increase in absolute chest wall volumes and associated chest wall diameters during the PLB compared to the QB performed within the same body positions observed in our older adults were in line with those previously reported in patients with COPD [13,17,21–24] . The increase in total and regional chest wall volumes has been shown to provide better gas exchange in the lungs and reduce the sensation of dyspnea [13,21] .…”

Forward trunk lean with arm support affects the activity of accessory respiratory muscles and thoracoabdominal movement in healthy individuals

“…Accordingly, the results of the study indicated that the magnitude of the anterior-to-posterior movement of the upper ribcage was greater in forward-leaning postures than in upright ones. The results were moreover consistent with those of Kim et al (2012). Although patients with chronic obstructive pulmonary disease (COPD) composed their study's sample, both their and our collection protocols allow evaluating the effect of gravity action on the mechanics of breathing.…”

“…Normally, the trunk is stabilized, and accessory respiratory muscles move the vertebral column, arm, head, and pelvis on the trunk (Starr & Dalton, 2011). When the shoulder girdle is fixed by arm support, the ribcage becomes the mobile segment (Banzett et al, 1988;Kim et al, 2012). The effect of the muscle's pull is transferred to the ribcage, and the SMC and Sc pull the sternum and the first two ribs, thereby increasing the thoracic diameter by moving the ribcage upward and outward in a pump-handle motion (Starr & Dalton, 2011).…”

“…That conflicting result could have stemmed from postural differences between postures. According to Kim et al (2012), in moving from a neutral sitting position (e.g., USit) to sitting with elbows on the knees, the decreased angle between the trunk and hips might increase the resistance of abdominal content to the downward movement of the diaphragm. However, in our study, that angle was maintained between USit and SitAS, which minimized the effect of leaning the trunk forward on the inward movement of the abdominal content against the diaphragm.…”

“…Sharp, et al (1980) indicated the decreased contribution of the upper ribcage muscles (e.g., sternocleidomastoideus, SCM, and scalenus, Sc) in postures involving leaning the trunk forward with arm support, which consequently reduced energy expenditure. Conversely, other authors have shown that arm support increases the recruitment of those muscles and thus contributes significantly to ribcage elevation (Banzett, Topulos, Leith, & Nations, 1988;Kim et al, 2012).…”