ASSOCIATION OF PECTORALIS MINOR TIGHTNESS WITH INSPIRATORY CAPACITY AND CHEST EXPANSION IN COLLEGE STUDENTS: A CORRELATIONAL STUDY

Background: The pectoralis minor muscle significantly contributes to scapular positioning and upper thoracic mobility. Tightness in this muscle is commonly observed in individuals with poor posture, such as rounded shoulders and forward head posture, which may restrict thoracic cage movement and affect breathing efficiency. Among students, prolonged sitting, use of electronic devices, and poor ergonomics can contribute to postural imbalances and increased muscle tightness. Since effective thoracic expansion is crucial for optimal breathing, it is important to investigate whether pectoralis minor tightness affects lung function and chest wall mobility. Understanding this relationship can aid in developing integrated musculoskeletal and cardiopulmonary rehabilitation strategies. Objective: The aim of this study was to determine the correlation between pectoralis minor tightness and inspiratory capacity, and to evaluate its relationship with thoracic expansion measured at the axilla, nipple, and xiphoid levels in healthy student participants. Methods: Eighty-five healthy students participated in the study. Pectoralis minor tightness was assessed using a standardized length test. Inspiratory capacity was measured using an incentive volumetric spirometer, and thoracic expansion was measured at three anatomical levels using a measuring tape. Pearson’s correlation test was used for analysis. Results: There was a modest, non-significant link between pectoralis minor tightness and thoracic expansion, but a substantial moderate correlation with inspiratory capacity (r = 0.309, p = 0.004). At the axillary level, there was a weak and negative correlation between thoracic expansion and pectoralis minor tension (r = – 0.194, p = 0.075).At the nipple level, there was a weak and statistically insignificant correlation between pectoralis minor tightness and thoracic expansion (r = 0.006, p = 0.956). Additionally, there was a slight and negative correlation (r = –0.189, p = 0.084) between thoracic extension at the xiphoid level and pectoralis minor tightness. Conclusion: Pectoralis minor tightness moderately affects inspiratory capacity but not regional thoracic expansion. Keywords: Pectoralis minor tightness, Thoracic expansion, Inspiratory capacity