Abstract
Introduction: Stroke induces several degrees of respiratory muscle dysfunction. Previous studies have reported higher positioning of the paretic hemidiaphragm associated with decreases in diaphragmatic excursions during spontaneous breathing. Inspiratory muscle training (IMT) has been shown to improve respiratory function in chronic stroke patients. However, there are no studies that have evaluated the effect of high-intensity IMT on these patients.Aims and Objectives: The purpose of this study was to evaluate the effect of high-intensity IMT on diaphragm thickness and the asymmetry of diaphragm thickness in chronic stroke patients.Methods: Sixteen chronic stroke patients (Mean age= 60.88 years) were assigned to two groups. The intervention group completed a six-week program of IMT set at 80% of maximum inspiratory effort. The training was performed three days each week. We evaluated the diaphragm thickness by ultrasonography. Pulmonary function and maximal inspiratory pressure (MIP) were measured at pre- and post-intervention.Results: High-intensity IMT group significantly increased diaphragm thickness ratio on non-paretic side (p<0.05), but control group showed no significant difference in diaphragm thickness ratio. The control group significantly increased asymmetry of diaphragm thickness (p<0.05), but intervention group showed no significant difference in asymmetry of diaphragm thickness.Conclusions: High-intensity IMT set at 80% of maximal effort resulted in increased contracted diaphragm thickness and decreased asymmetry of diaphragm thickness in chronic stroke patients.