Resisted Inspiratory Muscle Training Applied in Addition to PSSE-Schroth Exercises

Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity that may adversely affect thoracic volume, respiratory mechanics, postural symmetry, balance, functional capacity, and health-related quality of life. While physiotherapeutic scoliosis-specific exercises (PSSE), including the Schroth method, have demonstrated clinical benefit, the evidence regarding the added value of integrating structured inspiratory muscle training (IMT) with PSSE remains limited, particularly in studies using comprehensive physiological and biomechanical outcome sets. This prospective, randomized controlled trial will investigate whether adding resisted IMT to a standardized PSSE-Schroth program provides additional improvements in clinical outcomes in adolescents with AIS. Eligible participants will be females aged 10-18 years diagnosed with AIS, with Cobb angle between 10° and 45°, angle trunk rotation (ATR) ≥5°, and skeletal immaturity criteria consistent with Risser ≤3 and Sanders ≤4. Participants with non-idiopathic scoliosis, recent spine surgery/major trauma, contraindications to exercise, relevant systemic/neurological conditions, or recent participation in PSSE/IMT programs will be excluded. Participants will be randomly allocated to one of two groups: (1) PSSE-Schroth plus resistance IMT or (2) PSSE-Schroth alone. Both groups will receive supervised sessions for 8 weeks, three times per week (total 24 sessions). The independent variable is the exercise protocol, and dependent variables include clinical measures. The trial aims to provide a multidimensional evaluation of the potential additive effects of IMT when integrated with PSSE-Schroth, offering clinically relevant evidence to refine conservative rehabilitation strategies for AIS.