Rasch Analysis of the Wrist and Hand Fugl-Meyer: Dimensionality and Item-Level Characteristics.

Background And Purpose: Clinical administration of the wrist stability, wrist mobility, and hand items of the upper-extremity Fugl-Meyer (W/H UE FM) may provide a rigorous, easily administered, bedside measure of motor impairment in mildly impaired stroke survivors. The purpose of this study was to evaluate the item structure of the W/H UE FM to better understand its measurement properties using Rasch analysis.

Methods: This was a secondary analysis of W/H UE FM data arising from clinical trials of mildly impaired stroke survivors using latent parallel analysis, ordinal factor analysis, and partial credit model Rasch analyses.

Results: Latent parallel analysis and ordinal factor analysis indicated that all W/H UE FM items represent a single unidimensional construct, wrist and hand motor ability. Rasch analysis of data from 150 mildly impaired stroke survivors (94 men; mean age, 57.1 ± 11.4 years; mean time since stroke, 19.5 months) revealed that the W/H UE FM operated as a reliable, valid, and effective measure of wrist and hand motor ability. These data were compatible with Rasch model assumptions and are consistent with previous W/H UE FM research. Mass flexion and extension movements were the least difficult W/H UE FM items while the radial and hook grasp items were the most difficult.

Discussion And Conclusion: The W/H UE FM is well suited to mildly impaired stroke survivors who exhibit the ability to perform mass flexion and mass extension movements. The full-scale UE FM may be preferable for stroke survivors with lower levels of ability.Video abstract available for additional insight from the authors (Supplemental Digital Content 1, http://links.lww.com/JNPT/A108).