Measuring impairment and functional limitations in children with cerebral palsy

Objective.The disablement model provides a theoretical framework for the assessments of individuals with cerebral palsy (CP). The purpose of this study was to evaluate the relative validity of multiple measures for impairment and functional limitations and to estimate the relationship between the two global factors using confirmatory factor analysis. Methods.Over 50 measures of impairment and functional limitations were collected for 57 children with spastic CP. There were 12, 10, 5, 7 and 23 children who were classified in Gross Motor Function Classification System (GMFCS) Levels I to V, respectively. Results.The measures of impairment with the highest factor loadings were several single-item ratings of spasticity; the Modified Ashworth hamstring and biceps ratings, and goniometric measures. All of the functional limitation measures had high factor loadings, including the gross motor function measure, GMFCS, the Paediatric Evaluation of Disability Inventory and WeeFIM self care and mobility scales. The correlation between the global factors of impairment and functional limitations was 0.96, indicating that the two factors are highly correlated in spastic CP. Conclusion.The disablement model is a valuable theoretical tool that can be used to organise assessments in CP and to explain how they are related.