horse gait analysis

Horse gait analysis is getting more advanced: A recently developed and tested comprehensive motion sensor system can simultaneously record and analyze data remotely from eight parts of a moving horse body.

The strategically placed inertial measurement units (IMUs) on the horse can help evaluate gait and movement in a variety of situations, said Filipe Serra Bragança, DVM, a PhD candidate in equine musculoskeletal biology at Utrecht University’s Faculty of Veterinary Medicine Department of Equine Sciences, in The Netherlands.

By collecting kinematic movement data wirelessly from the horse’s poll, withers, sacrum, sternum (underside of the barrel), and each leg, veterinarians and even judges could complement their visual assessments of horses in motion, he said. Such a system could give critical information about lameness, neurological disorders, performance, and natural gaits.

“Similar IMU-based systems have used one to three sensors, but by using more sensors in different locations, like the body and the limbs, we can provide the users with additional relevant information,” Bragança said.

The research team’s eight-point system appears to be as reliable (if not more for measuring limb motion) than complex and expensive optical motion capture (OMC), or OMC camera-based systems working off a series of markers placed on the horse—the current “gold standard” of objective lameness evaluation, they said.

In their study, the scientists tested their system on seven sound Warmblood mares walking and trotting in hand in a straight line. At the same time, they measured the mares’ movement using the gold standard—about 10 to 15 reflective markers placed on horses’ bodies strategically and 18 infrared cameras recording motion capture data.

They found that their results closely resembled those provided by the motion capture infrared camera system, Bragança said, demonstrating good performance of the IMU.

“It is important that we work with validated and tested equipment,” he said.

Results differed mostly with regard to limb movement, but the researchers said that’s probably because the eight-point system is actually more reliable in certain situations than the camera system, which can’t detect leg movement as accurately because the cameras are not sensitive enough to depth perception on moving limbs. 

“We have come so far with technological developments that IMU sensors are becoming as accurate as OMC, or in some cases, even more accurate, since, in fact, the sensor inside the IMU, can measure limb angles directly, for example,” Bragança said. “We can’t assume that OMC is an ultimate gold-standard for all kinematic measurements since, as we’ve shown, IMUs can outperform motion capture when calculating some specific parameters and under some specific circumstances.”

Far from being limited to lameness evaluations, the sensor system could also help improve breeding programs by providing objective data about natural gaits in individuals, he said. And it could even lead to improved health monitoring in a practical setting.

“The fact that we can measure the complete locomotion of the horse at a distance opens perspectives for accelerating the use of these techniques to monitor horses during their sports performance, such as to detect abnormalities and thereby prevent injuries,” said Bragança. “The devices could also enable us in the near future, to keep track of our horses’ safety and welfare during daily training, competition, or even pasture activities for example.”

The system could come to the commercial market in coming years, the researchers said.

The study, “EquiMoves: A Wireless Networked Inertial Measurement System for Objective Examination of Horse Gait,” was published in Sensors