Dimensionality and Item-Difficulty Hierarchy of the Lower Extremity Fugl-Meyer Assessment in Individuals With Subacute and Chronic Stroke

Arch Phys Med Rehabil. 2016 Apr;97(4):582-589.e2. doi: 10.1016/j.apmr.2015.12.012. Epub 2015 Dec 29.


Objective: To investigate the dimensionality and item-difficulty hierarchy of the Fugl-Meyer Assessment of the lower extremity (FMA-LE).

Design: Secondary analyses of data pooled from 4 existing datasets: a phase III randomized controlled trial investigating the effectiveness of body weight support and a treadmill for rehabilitation of walking poststroke, and 3 cross-sectional studies investigating the link between impaired motor performance poststroke and walking.

Setting: University research centers and rehabilitation centers.

Participants: A pooled sample of individuals with a stroke (N=535, men=313; mean age ± SD, 61.91±12.42y).

Interventions: Not applicable.

Main outcome measures: Confirmatory factor analyses (CFA) and Rasch residual principal component analysis (PCA) investigated the dimensionality of the FMA-LE. The Rasch analysis rating scale model investigated item-difficulty hierarchy of the FMA-LE.

Results: The CFA showed adequate fit of a 3-factor model, with 2 out of 3 indices (CFA=.95; Tucker-Lewis Index=.94; root mean square error of approximation=.124) showing good model fit. Rasch PCA showed that removal of the reflex and coordination items explained 90.8% of variance in the data, suggesting that the abnormal synergy items contributed to the measurement of a unidimensional construct. However, rating scale model results revealed deviations in the item-difficulty hierarchy of the unidimensional abnormal synergy items from the originally proposed stepwise sequence of motor recovery.

Conclusions: Our findings suggest that the FMA-LE might represent a multidimensional construct, challenging the use of a total score of the FMA-LE to predict lower extremity motor recovery. Removal of the misfit items resulted in creation of a unidimensional scale composed of the abnormal synergy items. However, this unidimensional scale deviates from the originally proposed hierarchical ordering.

Keywords: Lower extremity; Rehabilitation; Stroke.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aged
  • Chronic Disease
  • Cross-Sectional Studies
  • Disability Evaluation*
  • Exercise Test / methods
  • Exercise Test / statistics & numerical data*
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Lower Extremity / physiopathology*
  • Male
  • Middle Aged
  • Principal Component Analysis
  • Psychometrics
  • Randomized Controlled Trials as Topic
  • Recovery of Function*
  • Retrospective Studies
  • Stroke / physiopathology*
  • Stroke Rehabilitation
  • Walking