Inspiratory Muscular Training in Chronic Stroke Survivors: A Randomized Controlled Trial

Objective: To assess the effectiveness of inspiratory muscular training (IMT) on measures of strength, resistance, functional performance, and quality of life (QOL) for chronic stroke survivors. Design: Double-blinded randomized controlled trial. Setting: Research laboratory. Participants: Subjects (N=21) with stroke (11 men, 10 women; maximal inspiratory pressure [MIP] <90% of predicted values) were randomly assigned to the experimental (n=11) and control groups (n=10); 18 participants completed all testing and training. Interventions: Interventions were based on home-based training, with resistance adjusted biweekly to 30% of MIP for the experimental group. The control group underwent the same protocol without the threshold resistance valve. Both groups received home training 30 minutes a day 5 times a week for 8 weeks. Main Outcome Measures: MIP, inspiratory muscular endurance (IME), functional performance, and QOL. Results: There were significant between-group differences for the MIP and IME measures. Significant changes were observed for only the experimental group for MIP (67.8 +/- 14.6 at baseline to 102.2 +/- 26.0cmH(2)O at posttraining) and IME (31.8 +/- 19.3 to 49.2 +/- 21.1cmH(2)O). No statistically significant differences were observed for measures of functional performance and QOL. Conclusions: Significant short-term effects of the IMT program for inspiratory strength and endurance were observed in chronic stroke survivors. These findings gave some indications that IMT may benefit people with stroke, and it is feasible to be included in rehabilitation interventions with this population.