Examining the Relationship Between COPD Severity and Thoracic Kyphotic Index: A Correlational Study

Background: Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory disorder frequently associated with postural alterations, particularly increased thoracic kyphosis. Such postural changes may further compromise respiratory mechanics, functional capacity and quality of life. Despite this clinical relevance, limited evidence exists regarding the relationship between COPD symptom severity and the degree of thoracic kyphosis. Objective: To examine the correlation between COPD symptom severity and thoracic kyphotic deformity using the Kyphotic Index. Methods: A correlational study was conducted on 30 clinically stable patients with COPD (aged 20–80 years), recruited from outpatient and inpatient settings. Thoracic kyphosis was assessed using the flexicurve method by tracing the thoracic spinal curvature from the C7 to T12 spinous processes in standing posture and calculating the Kyphotic Index. COPD symptom severity was evaluated using the COPD Assessment Test (CAT). Karl Pearson’s correlation coefficient was used for statistical analysis. Results: A statistically significant moderate positive correlation was observed between CAT scores and the Kyphotic Index (r = 0.668, p < 0.001), indicating that greater symptom burden is associated with increased thoracic kyphosis. Conclusion: Increased COPD symptom severity is associated with greater thoracic kyphotic deformity. These findings emphasize the importance of early postural assessment and targeted physiotherapy interventions to reduce functional decline and optimize respiratory efficiency in patients with COPD.