title: Diaphragmatic amplitude and accessory inspiratory muscle activity in nasal and mouth-breathing adults: a cross-sectional study.
abstract: The purpose of this study was to evaluate the electromyographic activity of the accessory inspiratory muscles and the diaphragmatic amplitude (DA) in nasal and mouth-breathing adults. The study evaluated 38 mouth-breathing (MB group) and 38 nasal-breathing (NB group) adults, from 18 to 30years old and both sexes. Surface electromyography (sEMG) was used to evaluate the amplitude and symmetry (POC%) of the sternocleidomastoid (SCM) and upper trapezius (UT) muscles at rest, during nasal slow inspiration at Lung Total Capacity (LTC) and, during rapid and abrupt inspiration: Sniff, Peak Nasal Inspiratory Flow (PNIF) and Maximum Inspiratory Pressure (MIP). M-mode ultrasonography assessed the right diaphragm muscle amplitude in three different nasal inspirations: at tidal volume (TV), Sniff and inspiration at LTC. The SCM activity was significantly lower in the MB group during Sniff, PNIF (p<0.01, Mann-Whitney test) and MIP (p<0.01, t-test). The groups did not differ during rest and inspiration at LTC, regarding sEMG amplitude and POC%. DA was significantly lower in the MB group at TV (p<0.01, Mann-Whitney) and TLC (p=0.03, t-test). Mouth breathing reflected on lower recruitment of the accessory inspiratory muscles during fast inspiration and lower diaphragmatic amplitude, compared to nasal breathing.
authors.affiliation: Department of Physical Therapy, Federal University of Santa Maria, Santa Maria, RS, Brazil; Graduate Program of Human Communication Diseases, Federal University of Santa Maria, Santa Maria, RS, Brazil. Electronic address: elaine.trevisan@yahoo.com.br.
authors.forename: Maria Elaine
authors.initials: ME
authors.lastname: Trevisan
authors.affiliation: Graduate Program of Human Communication Diseases, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Jalusa
authors.initials: J
authors.lastname: Boufleur
authors.affiliation: Methodist Faculty of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Juliana Corrêa
authors.initials: JC
authors.lastname: Soares
authors.affiliation: Department of Medical Clinics, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Carlos Jesus Pereira
authors.initials: CJ
authors.lastname: Haygert
authors.affiliation: Center of Health Sciences and Sport, Santa Catarina State University, Florianópolis, SC, Brazil.
authors.forename: Lilian Gerdi Kittel
authors.initials: LG
authors.lastname: Ries
authors.affiliation: Department of Physical Therapy, Federal University of Santa Maria, Santa Maria, RS, Brazil; Graduate Program of Human Communication Diseases, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Eliane Castilhos Rodrigues
authors.initials: EC
authors.lastname: Corrêa
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D003964:Diaphragm / Q000502:physiology*; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D008297:Male; D009058:Mouth Breathing; D018482:Muscle, Skeletal / Q000502:physiology; D009296:Nasal Cavity / Q000502:physiology*; D009334:Neck Muscles / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology; D055815:Young Adult
keywords: Diaphragm; Electromyography; Mouth breathing; Nasal obstruction; Respiratory muscles; Ultrasonography