The effect of inspiratory and expiratory loads on abdominal muscle activity during breathing in subjects “at risk” for the development of chronic obstructive pulmonary disease and healthy

Abstract

The abdominal muscle activity has been shown to be variable in subjects with chronic obstructive pulmonary disease (COPD) when respiratory demand increases and their recruitment pattern may change the mechanics, as well as the work and cost of breathing. The scientific evidence in subjects "at risk" for the development of COPD may be important to understand the natural history of this disease. This study aims to evaluate the effect of inspiratory and expiratory loads on the abdominal muscle activity during breathing in subjects "at risk" for the development of COPD and healthy. Thirty-one volunteers, divided in "At Risk" for COPD (n=17; 47.71±5.11years) and Healthy (n=14; 48.21±6.87years) groups, breathed at the same rhythm without load and with 10% of the maximal inspiratory or expiratory pressures, in standing. Surface electromyography was performed to assess the activation intensity of rectus abdominis (RA), external oblique and transversus abdominis/internal oblique (TrA/IO) muscles, during inspiration and expiration. During inspiration, in "At Risk" for COPD group, RA muscle activation was higher with loaded expiration (p=0.016); however, in Healthy group it was observed a higher activation of external oblique and TrA/IO muscles (p<0.050). During expiration, while in "At Risk" for COPD group, RA muscle activation was higher with loaded inspiration (p=0.009), in Healthy group TrA/IO muscle showed a higher activation (p=0.025). Subjects "at risk" for the development of COPD seemed to have a specific recruitment of the superficial layer of ventrolateral abdominal wall for the mechanics of breathing.

Comparison of activity and fatigue of the respiratory muscles and pulmonary characteristics between post-polio patients and controls: A pilot study

“…An example of this was shown in [ 29 ] where high density sEMG measurements of the quadriceps activity were used to discriminate between healthy subjects and subjects with PPS. In a recent example, sEMG of the abdominal muscles was used to compare a population at risk for Chronic Obstructive Pulmonary Disease (COPD) with healthy subjects [ 30 ]. The research group had a different recruitment pattern of abdominal muscles for the mechanics of breathing.…”