Validation of two-dimensional kinematic analysis of walk and sit-to-stand motions in dogs

Objective - To assess the intra- and interobserver repeatability of 2-dimensional (2-D) kinematic analysis of walk and sit-to-stand motions in dogs. Animals - 10 healthy adult Labrador Retrievers. Procedures - 10 dogs were filmed during walk and sit-to-stand motions. Five trials were recorded for each dog, 3 of which were digitized. Two observers manually marked 15 landmarks on each frame during the motions of interest for these 3 trials. Each observer repeated the procedure approximately 1 week later. The 2-D joint angles were calculated. Intra- and interobserver coefficients of multiple correlations (CMCs) were calculated for each joint angle-time history. Results - Intraobserver repeatability, assessed as the mean CMCs of 12 joint angle measurements made for 10 dogs by 2 observers, was good or excellent in 23 of 24 (96%) mean CMCs of the joints measured. Interobserver variation, assessed by comparing CMCs of measurements made by 2 observers on 10 dogs on 2 days, was good or excellent in 161 of 240 (67%) CMCs of joints measured. Conclusions and Clinical Relevance - Intraobserver repeatability of 2-D kinematic measurements made on digitized videotapes was excellent. Interobserver repeatability of these measurements was acceptable.