Effect of Inspiratory Muscle Training on Functional Capacity, Lung Function, and Quality of Life in Operated Adolescent Idiopathic Scoliosis: A Double-blind Randomized Controlled Trial.

Purpose: Adolescent idiopathic scoliosis (AIS) negatively impacts general health due to impaired lung function. While previous studies have explored exercise training for AIS, the effectiveness of postsurgical inspiratory muscle training (IMT) remains unexamined. This study aimed to evaluate IMT's effectiveness during the early postsurgical period in AIS patients.

Design: A double-blind, randomized, parallel-group clinical trial was conducted. Participants were unaware of group allocation.

Methods: Functional capacity (6-minute walk test), lung function, respiratory and peripheral muscle strength, quality of life (Scoliosis Research Society-22, Oswestry Disability Index), and dyspnea were assessed. The study included 24 AIS patients scheduled for surgery: 12 in the IMT group (IMG) and 12 in the control group (CG). IMT was administered at 60% maximum inspiratory pressure (MIP) for the IMG and 5% MIP for the CG. Primary outcomes were functional capacity; secondary outcomes included lung function, dyspnea, muscle strength, and quality of life.

Findings: Both groups experienced significant postoperative declines in forced expiratory volume in 1 second, peak expiratory flow, and forced expiratory flow at 25% to 75% of the pulmonary volume values on the second day. After 6 weeks, the IMG demonstrated significantly improved functional capacity, lung function, respiratory muscle strength, dyspnea, and quality of life compared with the CG (P < .05). Peripheral muscle strength did not differ significantly between groups (P > .05).

Conclusions: AIS patients experienced reduced functional capacity, lung function, and quality of life post surgery. Six weeks of IMT significantly improved these parameters, demonstrating its safety, efficacy, and clinical applicability in AIS patients.