Location on the Body of a Wearable Accelerometer Affects Accuracy of Data for Identifying Equine Gaits

Monitoring horse activity is a valuable aid for horse caretakers to provide recommendations to improve equine health. One method for monitoring equine activity is through the use of an accelerometer to determine exercise intensity. A three-axis accelerometer was installed at three locations on the equine to determine activity measurement accuracy for the walk, trot, and canter. The objectives were to determine which location results in the most accurate step count, threshold acceleration values for each gait, and correlations between the thresholds and horse characteristics. The accelerometer output was compared to step count as determined from video recordings. Threshold values to delineate between gaits were determined by the maximum and minimum acceleration values observed during each gait for all equines. The average frequency was identified for each gait, and distinct ranges were determined. The results revealed a significant difference (P = .02, α ≤ 0.05) between all three sensor locations and the video analysis. There was a strong, positive linear correlation between the number of steps from the accelerometer and video analysis (r = 0.926, P < .001). The front leg location had the highest correlation r = 0.963 (P < .001). While all sensors underestimated the step count, there was not a significant difference between the accelerometer on the front leg and the video analysis at the walk. The height of the equine significantly interacted with step frequency for the canter. An equine activity monitor using an accelerometer yields more accurate step counts when placed on the front leg of the horse, though horse height needs to be considered for the canter.