An article titled, “Visual lameness assessment in comparison to quantitative gait analysis data in horses” was published in the Equine Veterinary Journal from the British Equine Veterinary Association (BEVA). It was authored by Aagje M. Hardeman, Agneta Egenvall, Filipe M. Serra Bragança, Jan-Hein Swagemakers, Marc H. W. Koene, Lars Roepstorff, Rene van Weeren, Anna Byström.
The researchers noted that quantitative gait analysis offers objective information to support clinical decision-making during lameness workups, including advantages in terms of documentation, communication, education and avoidance of expectation bias.
Very little data exists comparing outcome of subjective scoring with the output of objective gait analysis systems. The aims of this clinical observational study were first to investigate between- and within-veterinarian agreement on primary lame limb. Second the study wanted to research lameness grade and determine relationships between subjective lameness grade and quantitative data. This part of the study focused on differences between 1) veterinarians, 2) live versus video assessment and 3) baseline assessment versus assessment following diagnostic analgesia.
Kinematic data were compared to subjective lameness assessment by clinicians with ≥8 years of orthopedic experience. Subjective assessments and kinematic data for baseline trot-ups and response to 48 diagnostic analgesia interventions in 23 cases were included. Between and within-veterinarian agreement was investigated using Cohen’s Kappa (κ). Asymmetry parameters for kinematic data (‘forelimb lame pattern’, ‘hindlimb lame pattern’, ‘overall symmetry’, ‘vector sum head’, ‘pelvic sum’) were determined and used as outcome variables in mixed models; explanatory variables were subjective lameness grade and its interaction with 1) veterinarian, 2) live or video evaluation and 3) baseline or diagnostic analgesia assessment.
Agreement on lame limb between live and video assessment was ‘good’ between and within veterinarians (median κ=0.64 and κ=0.53). There was a positive correlation between subjective scoring and measured asymmetry.
The relationship between lameness grade and objective asymmetry differed slightly between 1) veterinarians (for all combined parameters, p-values between p<0.001 and 0.04), 2) between live and video assessments (‘forelimb lame pattern’, ‘overall symmetry’, both p≤0.001), and 3) between baseline and diagnostic analgesia assessment (all combined parameters, between p<0.001 and 0.007).
Overall, between- and within-veterinarian agreement on lame limb was ‘good’, whereas agreement on lameness grade was ‘acceptable’ to ‘poor’. Quantitative data and subjective assessments correlated well, with minor though significant differences in the number of millimetres, equivalent to one lameness grade between veterinarians, and between assessment conditions. Differences between baseline assessment versus assessment following diagnostic analgesia suggest that addition of objective data can be beneficial to reduce expectation bias.