Which Respiratory Training is More Effective in Individuals with Ankylosing Spondylitis: 360-Degree Expansion Diaphragm Exercises or Standard Diaphragm Exercises? Randomized Controlled Trial

Purpose: Respiratory complications, though often asymptomatic, are a significant cause of morbidity and mortality in individuals with Ankylosing Spondylitis (AS). Despite the proven benefits of exercise in managing AS, limited evidence exists comparing conventional diaphragmatic breathing to novel, multidimensional approaches targeting full thoracic expansion. This study aimed to address this gap by evaluating the effectiveness of standard versus 360-degree expansion diaphragm breathing exercises—delivered with sensor-based feedback—in improving respiratory function, disease activity, and physical capacity in AS. Methods: Fifty individuals diagnosed with AS were randomized to either a standard diaphragm breathing group (DG) or a 360-degree expansion diaphragm group (360 DG). Both groups received supervised exercise interventions twice weekly for six weeks. Outcomes included pulmonary function tests (PFTs), maximal inspiratory and expiratory pressures (MIP/MEP), and AS-specific indices: BASFI, BASDAI, and BASMI. Results: Both groups demonstrated significant improvements in functional indices and respiratory parameters, with no statistically significant intergroup differences. Notably, FEV1/FVC improved in the DG group (p = 0.017), while FVC showed a significant increase in the 360 DG group (p = 0.007). Respiratory muscle strength (MIP and MEP) improved significantly in both groups. Conclusion: This randomized controlled trial is among the first to evaluate 360-degree expansive diaphragm breathing in AS. The findings suggest that both standard and sensor-guided breathing exercises are safe and effective in improving respiratory and functional outcomes. These results underscore the clinical relevance of incorporating tailored respiratory training into rehabilitation programs for AS, offering physiotherapists and clinicians flexible, evidence-based strategies to improve patient care.