Neuromuscular Fatigue in Chronic Obstructive Pulonary Disease

This study will include three experimental sessions for both COPD patients and healthy participants. These experimental sessions will be performed on three separate days. Each session will last between 1.5 and 2 hours. The first session will correspond to a familiarization session with the different tests that will be performed during the two next sessions. During this first session, different functional tests will be also performed : 1-minute sit-to-stand tests and postural tests, with and without a concomitant cognitive task. The second and third sessions will correspond to experimental sessions during which the participants will accomplish a fatiguing task in single or dual-task situation (randomized order). The cognitive task will be a memory cognitive task, called n-back task. The fatiguing tasks will involve submaximal isometric contractions of the knee extensors performed until task failure. The neuromuscular fatigue will be evaluated regularly during the fatiguing tasks (i.e. about each minute) using the magnetic stimulation of the femoral nerve in order to assess to central and peripheral determinants of the neuromuscular fatigue. Moreover, the autonomic nervous system activity (via cardiac recordings), perceived exertion and cognitive performance (in dual-task situation) will be continuously recorded during the fatiguing tasks. Before and after each fatiguing tasks, several questionnaires will be completed (i.e. mood, motivation, subjective workload) in order to evaluate the psychological determinants of performance.