Relationship between Breathing Movements of the Chest and Abdominal Wall and Respiratory Efforts of Healthy Subjects

Abstract

[Purpose] This study investigated the relationship between thoraco-abdominal wall movements and respiratory effort sensation with inspiratory resistive loads in healthy young male subjects. [Subjects] Fifteen healthy young male subjects participated in this study. [Methods] The respiratory effort sensation (modified Borg scale), thoraco-abdominal wall (bilateral upper chest and lower chest, abdomen) movements, respiratory rates, and breathing patterns were measured during quiet breathing and inspiratory resistive loaded breathing using three-dimensional motion analysis. The data were analyzed using a multiple comparison method and a generalized mixed model with Akaike’s information criterion (AIC). [Results] In proportion to the inspiratory resistive loads, the modified Borg scale, each thoraco-abdominal distance, and the predominance of thoracic breathing significantly increased, and the respiratory rate significantly decreased. The breathing movement of the left upper chest had the lowest AIC value for the modified Borg scale. [Conclusion] The results suggest that the upper chest movements, in particular, the left upper chest, reflect the respiratory effort sensation due to inspiratory resistive loads in healthy young male subjects.