Postural-ventilatory coupling in individuals with and without chronic obstructive pulmonary disease

Abstract

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is an endemic disease affecting the respiratory system and is also accompanied by postural control impairment, increased risk of fall and reduced quality of life. The precise mechanisms related to balance control is yet under investigation. Objective: The present study aims to investigate the postural-ventilatory coupling
in individuals with COPD and establishing its relationship with the clinical and functional status of this population. Methods: Eighteen individuals diagnosed with COPD were subdivided into moderate (N=8) and severe (N=10) groups according to their GOLD classification. Control group consists of 10 healthy individuals matched in age. The participant was instructed to perform the following tasks: (1) maintain the usual ventilatory pattern (eupnoea); (2) adopt a hyperventilation pattern, guided by a metronome (tachypnea). A single 40s trial was performed for each task. The anterior-posterior coordinates of center of pressure (CP) were
acquired using a force platform. The ventilation movements were registered through a thoracic belt. A two-way ANOVA was used for groups vs. tasks comparison, assuming a alpha level of 5%. Results: There was no difference in the control and COPD groups regarding physical and functional status (P-value always >0.208). However, a significant group effect was found for the temporal shift of postural-ventilatory coupling (F=11.357, P<0.001, ç2=0.476); specifically, the moderate COPD group exhibited a larger delay between ventilatory movements and postural sway (posttest P<0.001). There was no relationship between postural-ventilatory coupling measures and the clinical and functional status of COPD individuals. Conclusion: COPD is related to changes in postural-ventilatory coupling depending on its severity of the disease. This phenomenon could be a possible mechanisms accounting for the postural impairment usually observed in this population.