Assessing balance in non-disabled subjects with multiple sclerosis : Validation of the Fullerton Advanced Balance Scale

Objective: To validate the Fullerton Advanced Balance (FAB) scale for high-functioning non-disabled people with multiple sclerosis (PwMS). Design: Cross-sectional study. Participants: A convenience sample of early-diagnosed PwMS (N = 82; Expanded Disability Status Scale score ≤ 2.5) with disease duration ≤ 5 years and a control group of healthy volunteers (N = 45). Main outcome measures: FAB scale, Timed Up and Go test (TUG), 6 Min Walk Test (6MWT) and 25 Foot Walk Test (25FWT). Results: Six of the ten original FAB scale items were selected to represent a unidimensional construct. Only one factor with eigenvalues > 1.0 (1.90) was found. The new version of the scale reported a Cronbach alpha value of 0.65, and it was also statistically significantly correlated with TUG (r = -0.48). The new six-item scale, dubbed the FAB-short scale (FAB-s), discriminated between healthy volunteers and PwMS; moreover, both the FAB-s and the TUG test discriminated between the two PwMS subgroups: EDSS=0-1.5 (no disability) and EDSS=2-2.5 (minimal disability). Conclusions: FAB-s is a unidimensional clinical tool for assessing balance. The scale is a promising instrument for detecting subtle changes in balance performance in high-functioning PwMS.