Reliability and Feasibility of the Four Square Step Test for Use in Children with Cerebral Palsy: A Pilot Study

Abstract

Purpose: The ability to maintain standing balance with a moving base of support and while making rapid postural adjustments is important for independence in various functional activities. Clinical tests and measures have not addressed this ability in children with disability. This pilot study examined the feasibility and reliability of the Four Square Step Test (FSST) as a test of dynamic balance in children with cerebral palsy (CP). Method: Four children with CP (Gross Motor Function Classification Scale levels I-II) were tested on the FSST by 3 assessors on the first occasion (interrater reliability) and repeat-tested by 1 assessor after 2 weeks (test-retest reliability). Six children with typical development (TD) were tested on a separate occasion to explore any between-group difference in performance. Results: The FSST was easy to setup, required no specialized equipment, could be completed in 5 minutes, and might be carried out by clinicians with limited experience in pediatric therapy. It demonstrated excellent interrater reliability (ICC = 0.832) and test-retest reliability (ICC = 0.979) in children with CP. Compared with FSST times for children with TD (mean = 9.12 ± 2.67 seconds), times for children with CP (mean = 18.38 ± 9.02 seconds) were significantly slower (p = 0.019, Mann-Whitney U = -2.345). Conclusions and Recommendations: The pilot study provides initial evidence on the potential usefulness of the FSST as a test of dynamic standing balance in children with CP. This warrants further investigation of the clinimetric properties of the FSST using an adequate sample size.