Accuracy and precision of hind limb foot contact timings of horses determined using a pelvis-mounted inertial measurement unit.

The research discusses the accuracy and precision of detecting foot contact timings of horse using an inertial sensor mounted on its pelvis. It was found to be effective even at different speeds and directions, and in cases of hind limb lame horses.

Research Objective

This study was aimed at understanding the effectiveness of using an inertial sensor, mounted on a horse’s pelvis, in accurately determining the timings of foot contact during movement. It was conducted across different conditions – walking, trotting, variance in speed, and directions. The method was also tested on horses suffering from hind limb lameness.

Methodology

• Ten horses were used in the study, each of them mounted with an inertial sensor on their pelvis.
• The stride cycle was broken down into continuous movements, making footfall timings essential to understand the pattern.
• Foot contact was calculated based on vertical velocity events occurring immediately before the maximum sensor roll towards the opposite limb.
• The study spanned across different conditions such as varying speeds, directions and was also conducted on hind limb lame horses.

Findings

• It was found that the foot contact timings corresponded well with data obtained from a hoof-mounted accelerometer when the minimum velocity was used in the case of walking horses. The mean difference across the horses was 15 (18)ms.
• For trotting horses, the mean difference ranged from -4 (14)ms to 12 (7)ms depending on the condition, when the velocity zero-crossing was used.
• The stride segmentation method remained stable and accurate even when applied to hind limb lame horses.

Applications

• The research concludes with the potential application of this method in segmenting overground sensor data of various species, not limited to horses, thus making it a potentially useful tool in animal movement analysis.