Abstract
OBJECTIVE: To assess the reliability and validity of the Chinese version of the Selective Control Assessment of the Lower Extremity (SCALE) in children with spastic cerebral palsy (CP). METHODS: Forty-five children with spastic CP (mean age 7.29 years, SD 2.87 years, rang 4-16 years) were recruited. Internal consistency was measured using Cronbach's α, while test-retest and inter-rater reliability were evaluated using intra-class correlation coefficients (ICC). Construct validity was established through correlation and confirmatory factor analyses. Discriminative validity was assessed by comparing SCALE scores across varying GMFCS levels. RESULTS: The Chinese version of SCALE demonstrates high internal consistency (Cronbach's α = 0.91) and good reliability with ICCs exceeding 0.76 for test-retest and inter-rater assessments. It shows significant correlations with GMFCS (r = -0.76, p < 0.001) and Fugl-Meyer scales (r = 0.79, p < 0.001), confirming its validity. Confirmatory factor analysis supports a well-fitting model (χ (2)/df = 1.58, RMSEA = 0.08, SRMR <0.001, GFI = 0.98, AGFI = 0.90, CFI = 0.99, TLI = 0.98), with the latent variable's AVE at 0.59 and CR at 0.88. Discriminative validity is evident in significant differences across GMFCS levels (p < 0.001), notably between levels I and II, I and III, and I and IV (p < 0.05). CONCLUSION: The Chinese version of SCALE shows good reliability and validity for assessing lower limb selective movement control in children with spastic cerebral palsy in China. CLINICAL TRIAL REGISTRATION: https://www.chictr.org.cn/showproj.html?proj=205380, identifier ChiCTR2400083880.