Poststroke recovery mainly takes place within the first weeks to months and about 95% of the patients reach their maximum recovery 3 months after stroke onset. Poststroke rehabilitation is initiated as early as possible and aims to reduce functional consequences of stroke, allowing patients to integrate into the community. However, up to 75% of the patients remain disabled in the long term. Strikingly, about 20 to 30% of the patients show functional decline (i.e., learned-nonuse) in the long term - most often after having finished their intensive rehabilitation period - and even stroke survivors who have little or no residual disability are less physically active when compared to their age-matched peers.

Poststroke outcomes can be well predicted early after stroke. However, the deficits early after stroke and the outcomes are measured by standardized clinical tests performed in the laboratory. The drawback of these tests is that they provide information about the best possible abilities of the patients, as they are encouraged by therapists in testing situations. This so called "capacity" does not necessarily reflect what patients do in daily life situations (i.e., "performance" or "real world use").

With the growing interest in the patients' performance, various assessments that objectively measure activities in daily life situations have been developed in the last few years. These devices capture movement in daily life situations in a sensitive and objective way. An additional benefit is that they are less hampered by floor or ceiling effects when compared to clinical laboratory measurements (i.e., clinimetrics). Nevertheless, outcome of real world performance is hardly ever used in clinical trials aiming to determine the effectiveness of stroke rehabilitation interventions. Actually, until today, the natural course of performance remains largely unknown, as are predictors for this course. It is also unknown to which extend patients' subjective reporting of performance matches objectively measured performance. Finally, although it is believed that there is a threshold for, for example, real life use of the paretic arm and further improvement, there is no evidence as to what this threshold is in terms of clinical laboratory measurements.

The present prospective longitudinal cohort study fills in the gap regarding knowledge about the profile and predictability of two performance outcomes during the first year poststroke: engagement in physical activities and the use of the paretic upper limb. In addition, it will provide insight in how physical activity engagement and upper limb use measured by daily life assessments relate to standard clinical laboratory assessments. This knowledge is a prerequisite for the identification of patients' phenotypes and a first essential step towards the development of tailored (i.e., precision medicine), innovative rehabilitation interventions which enhance performance in terms of physical activities or upper limb use in daily life. The ultimate goal is to reduce poststroke disability and associated costs.

RE-USE is a prospective longitudinal observational cohort study of 120 first-ever stroke patients, who will be assessed 3, 10, 28, 90 and 365 days after stroke onset, as well as at discharge of the rehabilitation center.

Inclusion Criteria:

• First-ever ischemic or hemorrhagic stroke, confirmed by MRI-DWI and/or CT (recurrent strokes are allowed when already included in this study after a first-ever stroke)
• Paresis or paralysis of the arm and/ or leg
• Living independently before stroke (mRS >2)
• Age 18 years or older
• Written informed consent of the patient or its legal representative after participants' information

Exclusion Criteria:

• Contra-indications on ethical grounds (vulnerable persons)
• Neurological or other diseases affecting upper limb use and/ or physical activity before stroke
• Known or suspected non-compliance, drug or alcohol abuse

Admitted to hospital