title: Four Square Step Test in ambulant persons with multiple sclerosis: validity, reliability, and responsiveness.
abstract: The aim of this study was to establish the concurrent validity and relative and absolute reliability, define the minimal detectable change, and evaluate the floor and ceiling effects of the Four Square Step Test (FSST) in ambulant persons with multiple sclerosis (pwMS). Twenty-five pwMS performed the FSST on two occasions, 8.1±4.1 days apart. During the first testing, session participants also reported their fall history, performed the Berg Balance Scale, Dynamic Gait Index, and completed the Activities-Specific Balance Confidence Scale. Performance on the FSST was significantly (P<0.001) and strongly associated with performance on the Berg Balance Scale (rs=-0.84), Dynamic Gait Index (rs=-0.81), and Activities-Specific Balance Confidence Scale (rs=-0.78). Relative reliability of the FSST was excellent (ICC2,1=0.922). The minimal detectable change estimate for the FSST was 4.6 s. The FSST is a valid and reliable measure of dynamic standing balance in ambulant pwMS. However, because a substantial change (43%) is required to demonstrate a real change in individual performance, the FSST is unlikely to be sensitive in detecting longitudinal change in dynamic standing balance.
authors.affiliation: Program in Physical Therapy, Department of Physical Therapy and Athletic Training, Doisy College of Health Sciences, Saint Louis University, Missouri 63104, USA. jwagne34@slu.edu
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Wagner
authors.forename: Rosemary A
authors.initials: RA
authors.lastname: Norris
authors.forename: Linda R
authors.initials: LR
authors.lastname: Van Dillen
authors.forename: Florian P
authors.initials: FP
authors.lastname: Thomas
authors.forename: Robert T
authors.initials: RT
authors.lastname: Naismith
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data; D000328:Adult; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D015203:Reproducibility of Results