A fNIRS system will be used to measure the CPF activation. The subjects will walk at their preferred speed on 10 m 3 times and while doing a cognitive task (dual task) 3 times also (in a random order). The same test will be repeated five minutes later. The fNIRS system will be retired and the same test will be repeated 10 min later.
Brain activation can be studied using the Functional Near InfraRed Spectroscopy (fNIRS). It was shown that CPF activation during walking and during dual task could be different in stroke patients and in healthy subjects.~To date, fNIRS reliability is not completely established during walking and during dual task. Therefore, this study will examine the reproducibility of fNIRS parameters during simple walking and during dual task in healthy subjects and in stroke patients.