Validation of an equine inertial measurement unit system in clinically normal horses during walking and trotting.

This research paper investigates and validates an equine inertial measurement unit system attached to a horse’s hoof and compares it to a 3-D optical kinematics system during walking and trotting.

Methods

The study involved data collection from five clinically normal horses. The research aimed at comparing two different methods of kinematic data collection, namely:

• Inertial Measurement Unit (IMU) system: an electronic device rigidly attached to the hoof of the horse, measuring the force, angular rate, and sometimes the magnetic field surrounding the body of the moving horse.
• 3-D Optical Kinematic System: a camera-based measuring approach capturing three-dimensional motion of the horse.

During walking and trotting, five swing phases each of the right forelimb and hind limb of these horses were observed and recorded through both the systems. Variables such as linear and angular positions, velocities, and accelerations were then compared.

Results

The comparison resulted in interesting observations:

• High correlation (r > 0.8) was found in 25 out of the total 55 variables compared across the two systems.
• Moderate correlation (r > 0.5) was found in 18 variables.
• The lowest Root Mean Squared Errors (a measure of the differences between values predicted by a model/the estimator and the values observed) were found in the sagittal plane and orientation.
• More differences were observed between the two systems during small changes in motion.

Conclusion

Following the results, it was concluded that the equine IMU system appears suitable for use in examining linear and angular hoof motion during the swing phase while walking and trotting. However, the study also highlighted its limitations, making it currently unfit as a clinical tool for lameness evaluation. This is due to shortcomings in accuracy, attachment method, and the lack of an evaluation stance phase. Despite these limitations, the IMU system shows promising potential and can be further explored and improved for better and efficient utilization.