33rd Annual Scientific Meeting proceedings

Introduction
There is very limited data on canine shoulder kinematics in heathy dogs. The purpose of this study is to report in vivo shoulder kinematics, obtained via biplanar fluoroscopy, in healthy dogs during walk and trot gait.

Material and methods
Dogs underwent orthopedic examination and biplanar fluoroscopy while walking and trotting on a treadmill. A collection of three gait cycles was performed for each velocity for data analysis. Computed tomography was performed to obtain 3D bone models of the scapula and humerus that were manually superimposed to each fluoroscopic image. Descriptive statistics, non-parametric paired T-test (P<0.05) and Pearson correlation coefficients were used to compare the rotations (flexion-extension, abduction-adduction, internal-external rotation) and translations (cranio-caudal, medio-lateral, proximo-distal) of scapula and humerus.

Results
Eight frontlimbs of four dogs were analyzed. Breeds were mixed-breed (n=2) and English Setters (n=2). Mean age and body weight were 4.5±2.8 years and 18.1±2.0 kg. Among shoulder rotations, flexion-extension was the highest during walk and trot in both stance- (mean±SD: 135.5±6.7 °; 130.4±5.8°) and swing-phases (mean±SD: 122.1±5.2 °; 118.7±6.8 °) respectively. Among shoulder translations, cranio-caudal translation was the highest during walk and trot in both stance- (mean mean±SD: 2.4±2.1 mm; 4.7±2.0 mm) and swing-phases (mean±SD:  7.2±1.9 mm; 7.2 ±1.9 mm) respectively. Flexion-extension rotation and cranio-caudal translation were the most consistent shoulder motion (Pearson coefficient = 0.99 and 0.97 respectively). The abduction-adduction rotation was the most inconsistent shoulder motion (Pearson coefficient= 0.26).

Conclusions
Flexion-extension and cranio-caudal translation are the main shoulders motions occurring during walk and trot in healthy dogs.