Physical fitness in persons with hemiparetic stroke: Its structure and longitudinal changes during an inpatient rehabilitation programme

Objective: To test the hypothesis that the structure of fitness in patients with hemiparetic stroke can be categorized into impairment/disability, cardiopulmonary, muscular and metabolic domains, and to study longitudinal changes in their fitness during an inpatient rehabilitation programme. Design: Structure analysis of multiple fitness parameters with principlal component analysis (PCA), and a before and after trial. Setting: Tertiary rehabilitation centre in Japan. Patients: One hundred and seven consecutive inpatients with hemiparetic stroke. Intervention: A conventional stroke rehabilitation programme consisting of 80 minutes of physical therapy and occupational therapy sessions five days a week, and daily rehabilitation nursing for a median duration of 105.5 days. Main outcome measures: Principal component scores extracted from measurement of paresis/daily living (the Stroke Impairment Assessment Set (SIAS) and the Functional Independence Measure (FIM)); muscular (grip strength (GS), knee extensor torque, and cross-sectional areas of thigh muscles); metabolic (body mass index (BMI) and fat accumulation on CT); cardiopulmonary (heart rate oxygen coefficient (HR-O₂-Coeff) obtained with a graded bridging activity and a 12-minute propulsion distance). Results: PCA categorized the original 15 variables into four factors corresponding to paresis/activities of daily living, muscular, metabolic and cardiopulmonary domains, and explained 78.1 % of the total variance at admission and 69.6% at discharge. Except the metabolic domain, PCA scores for the other three domains improved significantly at discharge (paired t-test, p < 0.05). Conclusion: The hypothetical structure of fitness was confirmed, and the PCA scores were useful in following longitudinal changes of fitness during inpatient rehabilitation.