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.