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

Abstract

Objective To quantitatively define levels of upper extremity movement impairment using cluster analysis of Fugl-Meyer upper extremity (FM-UE) with and without reflex items. Design Secondary analysis of FM-UE individual item scores compiled from baseline testing of 5 studies with consistent testing procedures. Setting University and VA research centers. Participants: Individuals (N=−247) with chronic stroke (>6 months post-stroke). Interventions Not applicable. Main Outcome Measures Cut-off scores defined by total FM-UE scores of clusters identified by two hierarchical cluster analyses run on full sample of FM-UE individual item scores (with/without reflexes). Patterns of motor function defined by aggregate item scores of clusters. Results FM-UE scores ranged from 2–63 (mean=26.9±15.7) with reflex items and 0–57 (mean=22.1 ±15.3) without reflex items. Three clusters were identified. The distributions of the FM-UE scores revealed considerable overlap between the clusters, therefore four distinct stroke impairment levels were also derived. Conclusions For chronic stroke, the cluster analyses of the upper extremity FM support either a three or a four impairment level classification scheme.