Validity and reliability of the Sitting Assessment Scale in cerebral palsy

Aim: The aim of this study was to examine the validity and reliability of the Sitting Assessment Scale (SAS) in individuals with cerebral palsy (CP). Methods: The study included 34 individuals with a diagnosis of spastic CP. Individuals were evaluated with the Gross Motor Function Classification System and the Manual Ability Classification System. SAS and Trunk Control Measurement Scale (TCMS) were applied to the participants. The intraclass correlation coefficient (ICC) was calculated to determine the intraobserver and interobserver reliability of the scale scored by three different physiotherapists at two different time intervals. Internal consistency was calculated with Cronbach's alpha coefficient. The fit between SAS and TCMS for criterion-dependent validity was evaluated using Pearson Correlation Analysis. Results: According to the GMFCS level, 79.41% of the children were mildly (Level I-II), 14.71% were moderately affected (level III), and 5.88% were severely affected (level IV). Intra > observer and interobserver reliability values of SAS were extremely high (ICCinterrater > 0.923, ICCintrarater > 0.930). It was observed that the internal consistency of SAS had high values (Cronbach alpha(test) > 0.822, Cronbach alpha(retest) > 0.804). For the criterion-dependent reliability; positive medium correlations found between SAS with Total TCMS Static Sitting Balance (r = 0.579, p < 0.001), with TCMS Selective Movement Control (r = 0.597, p < 0.001), with TCMS Dynamic Reaching (r = 0.609, p < 0.001), and with TCMS Total (r = 0.619, p < 0.001). Conclusion: SAS was found to have high validity and reliability in children with CP. In addition, the test-retest reliability of the scale was also high. SAS is a practical tool that can be used to assess sitting balance in children with CP.