Journal of Sleep Disorders & Therapy
Open Access

Abstract

Effect of Body Position on Respiratory Muscle Activity in Subjects with Upper Costal or Costo-diaphragmatic Breathing Type

Rodolfo Miralles, Isabel Celhay, Rosa Cordova, Hugo Santander, Saúl Valenzuela, Aler Daniel Fuentes, Mario Felipe Gutiérrez and Ricardo Bull

Effect of body position on electromyographic (EMG) activity has been studied in the cranio-cervical-mandibular muscles, but its effect on the activity of respiratory muscles in subjects with different breathing types has not yet been elucidated. This study included two groups of twenty male subjects each, one with upper costal and the other with costo-diaphragmatic breathing type. EMG activity was recorded using bipolar surface electrode technique. Electrodes were placed on the sternocleidomastoid (SCM), diaphragm (DIA), and external intercostal (EIC) and Latissimus dorsi (LAT) muscles. EMG activity was recorded in standing and lateral decubitus positions, during the following tasks: [1] Normal quiet breathing; [2] speaking the word “Mississippi”; [3] forced deep breathing. EMG activity of DIA and EIC muscles was higher in the standing than in the lateral decubitus position during all tasks in both breathing groups (p<0.05), excepting DIA activity during task 2 in the costo-diaphragmatic group. EMG activity of LAT muscle was higher in the standing than in the lateral decubitus position during task 3 in both breathing groups (p<0.05). EMG activity of DIA activity was higher in subjects with upper costal than in subjects with costo-diaphragmatic breathing type in the standing position during all tasks and also in the lateral decubitus position during tasks 1 and 2 (p<0.05). EMG activity of ECM, EIC and LAT muscles was not significantly different between both breathing types in the studied body positions. The higher EMG activity observed in the standing than in the lateral decubitus positions in both breathing groups, suggests differences in the respiratory effort depending on the body position. The higher EMG activity observed in DIA muscle of subjects with upper costal than costo-diaphragmatic breathing types, suggests differences in the respiratory effort depending on the breathing type.