Thoracic and Upper Limb Muscle Strength Enhances 6-Minute Walk Test Performance in COPD Patients

Background : As a leading cause of morbidity, chronic obstructive pulmonary disease (COPD) is characterized by exercise intolerance resulting in dyspnea and decreased muscle strength. It is still unclear how strengthening the thoracic and upper limb muscles can increase exercise capacity as shown by the 6-Minute Walk Test (6MWT). Methods: Using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria, 30 stable COPD patients (19 males, 11 females; mean age 60.45 years) were recruited. A six-repetition maximum (6MWT) and a one-repetition maximum (1RM) exercise (bench press, thoracic pull-down) were performed by the participants to measure their upper-limb and thoracic muscle strength. A six-repetition maximum (6MWT) and a one-repetition maximum (1RM) exercise (bench press, thoracic pull-down) were performed by the participants to measure their upper-limb and thoracic muscle strength. Pearson’s correlation and regression analyses were conducted using SPSS 22, with significance set at p < 0.05. Results : PImax (r = 0.53, p < 0.001), 1RM bench press (r = 0.54, p < 0.021), and lat pull-down (r = 0.54, p < 0.021) all showed significant correlations with the 6MWT distance (mean 317 ± 61 meters). The results of regression analysis showed that lat pull-down strength (β = 0.75, p < 0.033) and PImax (β = 0.35, p < 0.001) were significant predictors of 6MWT performance. 6MWT had a negative correlation with dyspnea as measured by the Baseline Dyspnea Index (BDI) (r = -0.50, p < 0.021). Conclusions : The 6MWT performance of individuals with COPD is significantly predicted by the strength of their thoracic and upper limb muscles, indicating that specific strength training may improve ADLs and increase exercise tolerance. The findings imply that pulmonary rehabilitation programs ought to incorporate upper-limb and thoracic movements.