Nine-axis inertial measurement unit output discriminates activities of varying intensity in the dog.

OBJECTIVE: To explore relationships between 9-axis inertial measurement unit (IMU) output and activities of varying intensity in dogs of various sizes. ANIMALS: 20 healthy, agility course-trained dogs of various ages and sizes. PROCEDURES: Height, weight, body condition score, age, length from IMU to the ischium, and height of IMU to the floor were recorded. Dogs performed a series of activities (rest, walk, trot, and agility course) while wearing the IMU device. IMU and video output were reviewed by independent investigators. Correlations and multiple regression models were used to explore relationships between independent variables and IMU output. RESULTS: Calibration demonstrated excellent correlation and concordance between IMUs (intraclass correlation > 0.9) and that the IMUs reliably measured a known acceleration (gravity at rest). Resultant vector magnitude {sqrt[(x^2) + (y^2) + (z^2)]} normalized to body size was calculated from the data. IMU output clearly discriminates between activities of varying intensity in the dog. CLINICAL RELEVANCE: The inability to accurately measure chronic pain is a barrier to the development of new, or critical evaluation of, therapeutics. Activity monitors (AM) may be the ideal diagnostic target since they are small and provide objective data that can be collected while the pet remains in its natural environment. These results demonstrate the concurrent and predictive validity of the IMU tested. Our long-range goal is to validate an open-source algorithm for the IMU so activity in a pet's natural environment can be used as an outcome measure in future studies.

Carpal Extension Angles in Agility Dogs Exiting the A-Frame and Hurdle Jumps.

OBJECTIVES: The aim of this study was to determine the mean carpal extension angles in dogs participating in the A-frame and hurdle jumps, and to determine if the use of a carpal brace changed the carpal extension angle. STUDY DESIGN: Data from 13 healthy agility dogs were included. Approximately 1 cm square adhesive tape markers placed on both forelimbs served as anatomic landmarks for carpal angle measurement. Each dog was filmed landing after jumping over a bar and exiting the A-frame. Five valid trials on each obstacle were collected. The carpal braces were then applied and the dogs were allowed to navigate obstacles for 10 minutes. Once acclimated to the brace, an additional five valid trials were collected. Carpal extension was measured from the videos collected using a video analysis software. RESULTS: Without the carpal brace, the mean carpal extension angles ± standard deviations in dogs participating in the A-frame and hurdle jumps were 124.7 ± 11.9 degrees and 123.3 ± 6.3 degrees, respectively. With the carpal brace, the mean carpal extension angles ± standard deviations were 129.1 ± 11.4 degrees and 125.3 ± 7.3 for the A-frame and hurdle jumps, respectively. There was no clinically significant reduction as defined (>10 degrees) in carpal extension measurements with and without the brace. CLINICAL SIGNIFICANCE: The brace used in this study did not show a clinically significant reduction in carpal extension. However, multiple avenues for future research have been identified using these data.