Abstract

Introduction. In individuals with Parkinson's disease (PD), respiratory muscle weakness and rigid-ity, bradykinesia of abdominal muscles and stiffness of the chest wall, affect the respiratory component of voice intensity due to reduced pulmonary capacity and airflow needed to vibrate the vocal folds. It may be possible to improve voice production by strengthening respiratory muscles. The purpose of this study was to evaluate the effects of inspiratory and expiratory muscle training on voice production outcomes in individuals with PD.