Determining Objective Parameters to Assess Gait Quality in Franches-Montagnes Horses for Ground Coverage and Over-Tracking – Part 2: At Trot.

This research examines the use of 3D optical motion capture and inertial measurement units to assess the stride length and over-tracking distance of Franches-Montagnes horse’s gait at trot speed. The results are compared to the visual assessments of six breeding experts and provide insights for refining the definition of gait quality traits in horses.

Objective and Methodology

• The aim of this study was to identify movement patterns that have strong correlations to stride length (SL) and over-tracking distance (OTD) in horses. Ground coverage, referred to as how much distance is covered per stride and over-tracking, the distance the hind foot steps ahead of the print left by the front foot, were both visually evaluated by breeding experts and compared with actual measurements. This comparison was done to see if there were correlations between the scores of ground coverage and over-tracking from the experts, and the actual SL and OTD as measured using 3D Optical Motion Capture (OMC) and inertial measurement units (IMUs).
• The researchers used 24 Franches-Montagnes (FM) stallions with limb and body kinematics measured using 3D OMC during an incremental speed test on a treadmill at trot (3.3-6.5 m/s).

Findings

• The study revealed that the front limb stance duration and OTD measured with OMC, or the OMC parameters front limb stance duration and suspension duration measurable with IMUs, explained most of the variance in SL. This suggests that these factors significantly impact the stride length.
• For over-tracking distance, the variance was explained with OMC parameters suspension duration and hind limb contralateral pro-retraction angles or IMU-measurable parameters suspension duration and maximal pelvis pitch.
• Interestingly, the study showed four of the six breeding experts’ ratings were significantly correlated with parameters such as the front limb protraction angle and suspension duration that were determined objectively through OMC or IMUs.

Conclusion

• The researchers concluded that this technologically-based assessment approach could be more precise in defining gait quality traits. The correlative evaluation between the expert scores and objective measurements confirms the importance of these parameters in defining gait quality in horses.