The Equine Quality of Movement Score: How reliable is it?

Abstract

Visually assessing equine quality of movement in the field is a routine part of performance management and rehabilitation procedures. To improve this subjective process, an outcome measure to grade quality of movement has been developed. The Equine Quality of Movement Score (EQoMS) is a battery of 30 standardised in-hand movement tests with a paired word and number grading system and directives to guide scoring based on key features. Six assessors (3 equine physiotherapists and 3 specialist equine veterinarians) scored video footage of 20 horses performing these movement tests. Videos were presented for scoring in a randomised order over two rounds with a 2-week gap in between. Intra-rater reliability was excellent (Spearman’s rho = 0.95, P = <0.001), and inter-rater reliability using ranked scores was moderately strong (Spearman’s rho = 0.66–0.95, P = <0.001). Assessors agreed on the relative quality of movement but disagreed on the absolute magnitude of movement quality. The assessors' free-text comments indicated a bias towards making negative comments. Reflecting the EQoMS directives, different features were commented on for different gaits, figures of movement and surfaces. Differences in terminology were found in the comments made by specialist equine veterinarians and equine physiotherapists, with the latter avoiding directly commenting on lameness. The variation in scores and comments emphasises the subjective nature of movement quality. Even when given the same training and directives to guide scoring, individual assessors' weighting of qualitative and quantitative elements was different. Further refinement is required to improve agreement on characteristics of equine movement, and the reliability of the EQoMS.