Reliability of the Gross Motor Performance Measure

Abstract

Background and Purpose. The reporting of reliability coefficients and the method of their determination is expected of test developers. The purpose of this study was to estimate the interrater, intrarater, and test-retest reliability of the Gross Motor Performance Measure, a measure of quality of movement designed to accompany the Gross Motor Function Measure. Subjects. Subjects were 28 children (25 with cerebral palsy, 2 nondisabled, 1 with head injury) between the ages of 1 and 10 years. Methods. Reliability data were obtained from assessments of 19 therapists. Results. Intraclass correlation coefficients for reliability varied from .92 to .96 for the total scores and from .84 to .94 for the five attribute scores. Conclusion and Discussion. When the Gross Motor Performance Measure was administered by therapists who are familiar with the Gross Motor Function Measure and had a 1-day training workshop, reliability of the total scores was above recommended minimums. Scores of single attributes were less reproducible.