Evaluation of inertial measurement units as a novel method for kinematic gait evaluation in dogs.

OBJECTIVE: To evaluate the use of inertial measurement units (IMU) for quantification of canine limb kinematics.

METHODS: Sixteen clinically healthy, medium-sized dogs were enrolled. Baseline kinematic data were acquired using an optical motion capture system. Following this baseline data acquisition, a harness system was used for attachment of IMU to the animals. Optical kinematic data of dogs with and without the harness were compared to evaluate the influence of the harness on gait parameters. Sagittal plane joint kinematics acquired simultaneously with IMU and the optical system were compared for the carpal, tarsal, stifle and hip joints. Comparisons of data were made using the concordance correlation coefficient (CCC) test and evaluation of root mean squared errors (RMSE).

RESULTS: No significant differences were demonstrated in stance duration, swing duration or stride length between dogs instrumented with or without the harness, however, mean RMSE values ranged from 4.90° to 14.10° across the various joints. When comparing simultaneously acquired optical and IMU kinematic data, strong correlations were found for all four joints evaluated (CCC: carpus = 0.98, hock = 0.95, stifle = 0.98, hip = 0.96) and median RMSE values were similar across the joints ranging from 2.51° to 3.52°.

CONCLUSIONS AND CLINICAL RELEVANCE: Canine sagittal plane motion data acquisition with IMU is feasible, and optically acquired and IMU acquired sagittal plane kinematics had good correlation. This technology allows data acquisition outside the gait laboratory and may provide an alternative to optical kinematic gait analysis for the carpal, tarsal, stifle, and hip joints in the dog. Further investigation into this technology is indicated.