Related Experiment Video
Updated: Aug 4, 2026

Video Movement Analysis Using Smartphones (ViMAS): A Pilot Study
Published on: March 14, 2017
Interobserver reliability of the gross motor performance measure: preliminary results
S S Thomas1, C E Buckon, D S Phillips
1Shriners Hospitals for Children, Portland, OR 97201-3095, USA.
Insights
The Gross Motor Performance Measure (GMPM) reliably assesses movement quality in children with cerebral palsy (CP). Its interobserver reliability is fair to good and improves with continued use.
Area of Science:
- Pediatrics
- Neurology
- Rehabilitation Medicine
Background:
- Assessing movement quality in children with cerebral palsy (CP) presents challenges.
- The Gross Motor Performance Measure (GMPM) was developed to aid this assessment.
- Understanding the reliability of the GMPM is crucial for its clinical application.
Purpose of the Study:
- To determine the interobserver reliability of the Gross Motor Performance Measure (GMPM).
- To evaluate if GMPM reliability improves with ongoing use.
Main Methods:
- Thirty-six children with spastic CP (mean age 7 years) were assessed using four GMPM dimensions.
- Interobserver reliability was calculated using Percent Agreement, Intraclass Correlations, and Kappas.
- Reliability was analyzed over time to assess improvement with use.
Main Results:
- Overall interobserver reliability for the GMPM was found to be in the 'fair to good' range.
- Reliability scores demonstrated improvement over time.
- More individual item scores moved from 'fair to good' to 'excellent' categories with continued use.
Conclusions:
- The Gross Motor Performance Measure (GMPM) provides a reliable method for assessing movement quality in children with cerebral palsy.
- The GMPM's reliability is adequate for clinical use and potentially improves with practice.
Abstract:
Although assessment of the quality of movement in children with cerebral palsy (CP) is difficult, the development of the Gross Motor Performance Measure (GMPM) has facilitated this process. In order to determine the interobserver reliability of the GMPM, 36 children with spastic neuromuscular disorders (mean age 7 years, range 4 to 15 years) were evaluated using four of the five dimensions of the GMPM. Percent Agreement, Intraclass Correlations, and Kappas were calculated by both dimension and attribute to determine reliability. In addition, reliability measures were evaluated over time to determine whether reliability improved with continual use of the GMPM. Overall, interobserver reliability was in the 'fair to good' category regardless of the reliability measure used in the analysis. Reliability scores improved over time with a greater number of individual item scores moving from the 'fair to good' category to the 'excellent' category. Results from this study indicate that it is possible to assess reliably the quality of movement in children with CP.

