Effect of cervicothoracic posture on respiratory muscle strength and upper extremity function in healthy young adults

BackgroundThe effects of changes in cervicothoracic posture on respiratory and exercise capacity in healthy young adults are still debated.ObjectiveThis study aimed to investigate the effect of cervicothoracic posture on respiratory muscle strength and upper extremity function and to compare according to the activity levels in healthy young adults.MethodsNinety-three healthy young adults were included in this study. Cervicothoracic posture, including the craniovertebral angle, cervical lordosis angle, forward shoulder angle (FSA), and thoracic kyphosis angle, was assessed using the photographic method. Chest wall mobility, respiratory muscle strength, upper extremity function, physical activity level, and severity of fatigue were assessed. Pearson's correlation analysis revealed significant associations between respiratory muscle strength and cervicothoracic posture, as well as anthropometric measures. Multiple linear regression identified independent predictors of MIP and MEP, adjusting for potential confounders such as smoking.ResultsThe FSA demonstrated a weak but statistically significant correlation with both maximum inspiratory pressure (MIP) (r = -0.248, p = 0.021) and maximum expiratory pressure (MEP) (r = -0.219, p = 0.041). Axillary circumference measurements demonstrated a near-significant association with MEP (B = 4.93, p = 0.059). Upper extremity function did not correlate with cervicothoracic posture (p > 0.005). The MEP was significantly associated with fatigue severity (B = - 0.02, β = - 0.323, p = 0.022). Activity level was associated with MEP, chest mobility and fatigue (p < 0.05).ConclusionCervicothoracic posture does not affect respiratory muscle strength or upper-extremity function in healthy young adults. The MEP is influenced by axillary chest mobility and affects fatigue. Activity is important for the respiratory health of healthy young adults.