Relationship and responsiveness of muscular function and functional tests in patients with COPD

Background: The relationship between, and responsiveness of, performance in functional tests and muscular strength in patients with chronic obstructive pulmonary disease (COPD) has been established. However with regard to peripheral muscular endurance less is known. Aim: To determine the relationship between and responsiveness of upper and lower limb muscular strength and endurance to functional tests in patients with COPD Methods: The study was a secondary analysis of a randomized controlled trial. Twenty-two patients with COPD (FEV 1 58.7% predicted), randomized to an 8-week resistance training regimen were included. The 6-minute walk test (6MWT), 6-minute pegboard and ring test, unsupported upper limb exercise test (UULEX), and isokinetic shoulder flexion and knee extension muscular strength and endurance were assessed. Spearman rank correlation (r) and standardized response means (SRM) were used. Results: Both knee strength (r=.53, p=.011) and knee endurance (r=.74, p Conclusions: These results indicate that muscular endurance may be more related to functional capacity than muscular strength in patients with COPD. Included tests ware demonstrated to be responsive to a resistance training regimen.