INTRODUCTION: Assessing gait adaptation in children with cerebral palsy (CP) requires cost-effective and easily applicable methods. OBJECTIVE: To evaluate the reliability and validity of the Walking Adaptability Ladder Test for Kids (WAL-K) in assessing gait adaptation in children with CP. METHODS: Sixty-six participants (40 children with CP and 26 controls), aged 6-18 years, underwent WAL-K testing under single- and double-run conditions with video recording. Test-retest reliability, interrater reliability, concurrent validity, and known-group validity were assessed. Concurrent validity was assessed using the Timed Up and Go Test (TUGT), Four-Square Step Test (FSST), and Five Times Sit-to-Stand Test. RESULTS: Interrater intraclass correlation coefficients (ICC3,k) values were >
0.999 for the WAL-K single- and double-run tests. The test-retest reliability ICC3,k values were 0.988 for the WAL-K single-run, and 0.963, 0.962, and 0.963 for the WAL-K double-run ( CONCLUSION: The WAL-K test demonstrated validity and reliability, making it suitable for clinical use without requiring specialized laboratory settings. It enables repeated assessments of gait adaptation in children with CP.