Relationship between objective and subjective assessment of limb function in normal dogs with an experimentally induced lameness.

Authors: 
Waxman AS, Robinson DA, Evans RB, Hulse DA, Innes JF, Conzemius MG.
Volume: 
37
Number: 
3
Pages: 
241-6
Journal: 
Vet Surg
Date: 
2008 Apr

OBJECTIVE: To evaluate the relationship between previously used subjective and objective measures of limb function in normal dogs that had an induced lameness. STUDY DESIGN: Prospective, blinded, and induced animal model trial. ANIMALS: Normal, adult, and mixed-breed dogs (n=24) weighing 25-35 kg. METHODS: Force platform gait analysis was collected in all dogs before and after induction of lameness. All gait trials were videotaped; 60 video trials were evaluated by 3 surgeons with practice limited to small animal orthopedics and 3 first year veterinary students in an effort to establish the relationship between subjective and objective measures of lameness. Evaluators were unaware of the force platform data. RESULTS: Concordance coefficients were low for all observers and were similar between students and surgeons. These values were further decreased when normal and non-weight bearing trials were removed. Agreement with the force platform data was low even when observers only had to be within +/-10% of the ground reaction forces. When repeat trials were evaluated surgeons had a much higher repeatability compared with students. CONCLUSIONS: Subjective evaluation of the lameness in this study varied greatly between observers and agreed poorly with objective measures of limb function. CLINICAL RELEVANCE: Subjective evaluation of gait should be interpreted cautiously as an outcome measure whether performed from a single or from multiple observers.