Reliability and Responsiveness of the Observable Movement Quality Scale for Children with Mild to Moderate Motor Impairments

Abstract

Aim: The Observable Movement Quality (OMQ) scale measures generic movement quality and is used alongside standardized age-adequate motor performance tests. The scale consists of 15 items, each focusing on a different aspect; together, the entire construct of movement quality is assessed. This study aimed to determine interrater and intrarater reliability, and responsiveness of the OMQ scale. Methods: A prospective intervention study with pre-post design in pediatric physical therapy practices. For interrater reliability, 3 physical therapists observed video-recorded motor assessments of 30 children with mild to moderate motor impairments —aged 4 to 12 years—using the OMQ scale. One therapist scored baseline assessment a second time for intrarater reliability, and to calculate smallest detectable change (SDC). Responsiveness (n = 28) was tested by comparing outcomes before and after intervention. Results: Interrater reliability was moderate to good (ICC2,1: 0.79); intrarater reliability was high (ICC2,1: 0.97). Responsiveness results revealed an SDC of 2.4 and a minimal important change of 2.5; indicating sufficient validity in differentiating groups of children showing improved versus unchanged movement quality. Conclusion: The OMQ scale is reliable and responsive to change when used to assess movement quality in clinical practice for children with mild to moderate motor impairments, aged 4–12 year.