title: 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.
authors.affiliation: Department of Physiotherapy, and Activity and Human Movement Study Center (CEMAH), School of Allied Health Technologies, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 400, 4200-072 Porto, Portugal; Faculty of Sport, CIFI2D, and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, Rua Dr. Plácido Costa 91, 4200-450 Porto, Portugal. Electronic address: antoniomesquitamontes@gmail.com.
authors.forename: António
authors.initials: A
authors.lastname: Mesquita Montes
authors.affiliation: Department of Physiotherapy, and Activity and Human Movement Study Center (CEMAH), School of Allied Health Technologies, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 400, 4200-072 Porto, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Crasto
authors.affiliation: Department of Physiotherapy, and Activity and Human Movement Study Center (CEMAH), School of Allied Health Technologies, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 400, 4200-072 Porto, Portugal.
authors.forename: Cristina Argel
authors.initials: CA
authors.lastname: de Melo
authors.affiliation: Department of Physiotherapy, and Activity and Human Movement Study Center (CEMAH), School of Allied Health Technologies, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 400, 4200-072 Porto, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Santos
authors.affiliation: Cardiovascular, Respiratory and Sleep Technician, Private Practice, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Pereira
authors.affiliation: Faculty of Sport, CIFI2D, and Porto Biomechanics Laboratory (LABIOMEP), University of Porto, Rua Dr. Plácido Costa 91, 4200-450 Porto, Portugal.
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Vilas-Boas
mesh_terms: D000328:Adult; D064131:Back Muscles / Q000502:physiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D017568:Rectus Abdominis / Q000502:physiology*; D015656:Respiratory Mechanics
keywords: Core abdominal; GOLD “Stage 0”; Respiration; Respiratory loads