The purpose of this study is to elucidate pathophysiological mechanisms behind gait disturbances during the early recovery phase after hemiparetic stroke to identify targets for new treatment strategies. Using an explorative, observational study design, pathophysiological mechanisms at play during the early recovery phase will be monitored, by repeated clinical assessments during inpatient rehabilitation as well as examinations of muscle activation patterns, kinematics of walking, corticospinal and reticulospinal function \< 1 month, 3 and 6 months after hemiparetic stroke. Inclusion: Eligible patients will have suffered a stroke, verified by CT or MRI examination and are admitted to inpatient care at the University Department of Rehabilitation Medicine Danderyd Hospital (RUDS). Thirty patients will be included consecutively. With an anticipated loss of 4-10 patients, at least 20 are expected to complete the study. The clinical assessment protocols include standardized measures for the assessment of clinical and self-perceived aspects of functioning and disability. These assessments will be performed and repeated \< 1 month, at 3 months and 6 months post-stroke by a therapist not responsible for rehabilitation interventions. At each of these assessment instances, laboratory movement analysis including electromyography (EMG) and ultrasound of the lower extremity muscle will be performed. In addition, a short assessment of body function and activity will be performed weekly during inpatient rehabilitation.