Postural Control Performance on the Functional Reach Test: Validity of the Kids-Balance Evaluation Systems Test (Kids-BESTest) Criteria

Evaluate the validity of the Kids-Balance Evaluation Systems Test (Kids-BESTest) clinical criteria for the Functional Reach Test (FRT) forward and lateral with laboratory measures of postural control in children with cerebral palsy (CP). Psychometric study of face, concurrent, and content validity. Clinical laboratory. Children (N=58) aged 7-18 years (ambulant CP n=17, typically developing [TD] n=41). Not applicable. Stability limits in standing were assessed using the Kids-BESTest items for FRT forwards (FRTFORWARD), FRT lateral preferred (FRTLATERAL(P)), and FRT lateral nonpreferred (FRTLATERAL(NP)). Force platforms and kinematic markers were used to collect information on center of pressure (CoP) and joint movement during reach. Analyses included face validity (Kids-BESTest scores compared between CP and TD groups), concurrent validity (agreement between Kids-BESTest scores and digitally derived scores), and content validity (relations between Kids-BESTest scores with kinematic and CoP data). Face validity of Kids-BESTest criteria was demonstrated with lower scores for CP compared to TD groups for FRTFORWARD (P