The Reliability and Validity of Korean Pediatric Functional Muscle Testing in Children with Motor Disorder

Purpose: This study was conducted to develop a Korean version of the pediatric functional muscle test (K-PFMT) for children with motor developmental disorders, and to verify its reliability and validity. Methods: The subjects were 40 children, aged below 5 years. Each was scored on the K-PFMT by 14 physical therapists to determine inter-rater reliability and internal consistency. Additionally, 3 of the 14 therapists tested 20 children again one or two weeks later to determine test-retest reliability. The internal consistency was calculated by Cronbach’s alpha. The inter-rater and test-retest reliability were calculated using the intraclass correlation coefficient (ICC). One-way ANOVA and the paired t-test were used to compare differences among the three evaluator groups and between the test and retest group. Concurrent validity was evaluated by Pearson’s correlation with a total score of GMFM. Results: Chronbach’s alpha was over 0.98 for each test item and 0.99 for the total items. There was no significant differences in the score of K-PFMT among the three evaluator groups except for a few items. The test-retest ICC was from 0.89 to 1.00 and from 0.82 to 1.00, respectively. There was no significant difference between the test and retest group, except for a few items. There were high significant correlations between K-PFMT and GMFM. Conclusion: This study showed that a K-PFMT with relatively high reliability and validity was successfully developed. The K-PFMT will be a useful tool for measurement of muscle strength of children with motor developmental disorder.