Minimal Detectable Change and Minimal Clinically Important Difference of Bruininks-Oseretsky Test of Motor Proficiency Second Edition Balance Component in Patients With Cerebral Palsy: A Pilot Study

Background Balance deficits are among the most disabling features of spastic cerebral palsy (CP), limiting mobility and participation. The balance subtest of the Bruininks-Oseretsky Test of Motor Proficiency Second Edition (BOT-2) in paediatric physiotherapy is widely used; however, its minimal clinically important difference (MCID) and minimal detectable change (MDC) for spastic CP children have not been reported. Hence, in spastic CP children, the current study primarily aimed to determine the MCID and MDC for the balance subtest of the BOT-2 and, as a secondary objective, to examine its concurrent validity with the Pediatric Balance Scale (PBS). Methods A total of 30 spastic CP children (Gross Motor Function Classification System (GMFCS) Levels I-II; mean age 8.35 ± 1.93 years) were assessed using the PBS and balance subtest of BOT-2 by two independent physiotherapists at baseline and after four weeks of conventional physiotherapy. The MDC and MCID were estimated with the PBS as the external anchor. Paired t-tests and Pearson correlation coefficients were applied for inferential analysis. Results Statistically significant improvements were observed in BOT-2 Balance and PBS scores for both assessors (p < 0.001). The MDC ranged from 1.5 to 1.7 points. Moderate-to-strong correlations were identified between BOT-2 and PBS change scores (r = 0.583-0.604, p ≤0.001). An MCID of ≥3.5 points across both assessors was consistently identified, with good-to-excellent discriminative capacity (AUC = 0.814-0.884). Conclusion The BOT-2 Balance subtest demonstrates good responsiveness in children with spastic CP. These preliminary findings provide an MDC of 1.5-1.7 points and an MCID of ≥3.5 points, providing evidence-based benchmarks for interpreting clinically meaningful balance improvement, supporting the integration of BOT-2 Balance into routine paediatric physiotherapy assessment.