Determining Levels of Upper Extremity Movement Impairment by Applying a Cluster Analysis to the Fugl-Meyer Assessment of the Upper Extremity in Chronic Stroke

OBJECTIVE:To quantitatively determine levels of upper extremity movement impairment by using a cluster analysis of the Fugl-Meyer Assessment of the Upper Extremity (FMA-UE) with and without reflex items. DESIGN:Secondary analysis. SETTING:University and research centers. PARTICIPANTS:Individuals (N=247) with chronic stroke (>6mo poststroke). INTERVENTIONS:Not applicable. MAIN OUTCOME MEASURES:Cutoff scores defined by FMA-UE total scores of clusters identified by 2 hierarchical cluster analyses performed on the full sample of FMA-UE individual item scores (with and without reflexes). Patterns of motor function defined by aggregate item scores of clusters. RESULTS:FMA-UE scores ranged from 2 to 63 (mean, 26.9±15.7) with reflex items and from 0 to 57 (mean, 22.1±15.3) without reflex items. Three clusters were identified. The distributions of the FMA-UE scores revealed considerable overlap between the clusters; therefore, 4 distinct stroke impairment levels were derived. CONCLUSIONS:For chronic stroke, the cluster analysis of the FMA-UE supports either a 3- or a 4-impairment level classification scheme.