Is there an association between quadriceps muscle endurance and performance on activities of daily living in individuals with COPD?

Abstract Introduction Chronic obstructive pulmonary disease (COPD) is characterized by limited airflow associated with inflammatory response and systemic manifestations, such as dyspnea, as well as physical inactivity and intolerance to exercise. The sum of these changes can lead to peripheral muscle fatigue and exert an impact on the performance of activities of daily living (ADL). Objective To investigate the possible association between peripheral muscle fatigue and performance on ADL in individuals with COPD, and to compare the results to those of healthy age-matched individuals. Methods Individuals with a diagnosis of COPD and healthy volunteers aged 60 years or older were submitted to evaluations of peripheral muscle fatigue (using surface electromyography) and performance on the Glittre-ADL test. Results Nine individuals with COPD and ten controls were evaluated. Median isometric quadriceps contraction time was 72 [38] and 56 [51] seconds, respectively. Execution time on the ADL test was 6.1 [4] and 3.6 [1.3] minutes for COPD and control group respectively, with a significant difference between groups (p < 0.05). However, no significant correlation was found between the evaluations. Conclusion No association was found between quadriceps muscle fatigue and performance on ADL in the sample studied. In the intergroup comparison, the individuals with COPD exhibited worse ADL time execution, but no significant difference was found regarding quadriceps muscle fatigue.