title: Abdominal muscle activity during breathing with and without inspiratory and expiratory loads in healthy subjects.
abstract: Central Nervous System modulates the motor activities of all trunk muscles to concurrently regulate the intra-abdominal and intra-thoracic pressures. The study aims to evaluate the effect of inspiratory and expiratory loads on abdominal muscle activity during breathing in healthy subjects. Twenty-three higher education students (21.09±1.56years; 8males) breathed at a same rhythm (inspiration: two seconds; expiration: four seconds) 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, external oblique and transversus abdominis/internal oblique muscles, during inspiration and expiration. During inspiration, transversus abdominis/internal oblique activation intensity was significantly lower with inspiratory load when compared to without load (p=0.009) and expiratory load (p=0.002). During expiration, the activation intensity of all abdominal muscles was significantly higher with expiratory load when compared to without load (p<0.05). The activation intensity of external oblique (p=0.036) and transversus abdominis/internal oblique (p=0.022) was significantly higher with inspiratory load when compared to without load. Transversus abdominis/internal oblique activation intensity was significantly higher with expiratory load when compared to inspiratory load (p<0.001). Transversus abdominis/internal oblique seems to be the most relevant muscle to modulate the intra-abdominal pressure for the breathing mechanics.
authors.affiliation: Department of Physiotherapy, and Activity and Human Movement Study Center (CEMAH), School of Allied Health Technologies, Polytechnic Institute of Porto, Rua Valente Perfeito 322, 4400-330 Vila Nova de Gaia, 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: Physiotherapist, Private Practice, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Baptista
authors.affiliation: Department of Physiotherapy, and Activity and Human Movement Study Center (CEMAH), School of Allied Health Technologies, Polytechnic Institute of Porto, Rua Valente Perfeito 322, 4400-330 Vila Nova de Gaia, 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 Valente Perfeito 322, 4400-330 Vila Nova de Gaia, 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 Valente Perfeito 322, 4400-330 Vila Nova de Gaia, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Santos
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: D000009:Abdominal Muscles / Q000502:physiology*; D000071596:Abdominal Oblique Muscles / Q000502:physiology; D000293:Adolescent; D000886:Anthropometry / Q000379:methods; D004576:Electromyography / Q000379:methods; D045853:Exhalation / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D008297:Male; D011187:Posture / Q000502:physiology; D011312:Pressure; D017568:Rectus Abdominis / Q000502:physiology; D012119:Respiration; D055815:Young Adult
keywords: Core abdominal; Postural control; Respiration; Respiratory loads; Surface electromyographic activity