Detection of Equine Hoof Motion by Using a Hoof-Mounted Inertial Measurement Unit Sensor in Comparison to Examinations with an Optoelectronic Technique - A Pilot Study.

This study aimed to determine whether a hoof-mounted inertial measurement unit (IMU) system would provide similar timing characteristics and step lengths, in walk and trot on different grounds, compared to those of an established optoelectronic motion system. The right hoof of one horse was equipped with an IMU sensor with an optical reference marker on top. Fifteen steps on firm ground, and five on penetrable ground, were performed at walk and trot. Level of agreement between the two measurement systems was determined by assessing the concordance correlation coefficients, accuracy, and precision of the duration of different gait events and step length. Timing characteristics and step length were in strong agreement between the two techniques for the majority of assessed parameters in walk and trot on both grounds. The agreement between techniques decreased for breakover and landing duration at trot on penetrable ground. Disparity between the measurement techniques was related to difficulties in accurately defining single parts of the stance phase with marker-based optoelectronic analysis on penetrable ground. Detailed examinations of different parts of the stance phase are more accurately performed using hoof-mounted IMU sensors. Results emphasise the great potential of IMU sensors for equine motion analysis in daily practice.