Quantification of equine sacral and iliac motion during gait: a comparison between motion capture with skin-mounted and bone-fixated sensors.

The research article discusses a study on the movement at the ilium and sacrum (parts of the horse’s spine) during normal gait in horses, specifically comparing the results from sensors fixed to the skin with those fixed to bone-implanted pins. The aim is to enhance understanding of the biomechanics of the equine sacroiliac joint.

Overview of the Study

• The objective of this study was to determine the movement at the ilium and sacrum in horses while they walk and trot using three-dimensional (3D) orientation sensors. The study also aimed to compare the results obtained from sensors attached to the skin and sensors attached to bone-implanted pins.
• The research involved six Thoroughbred horses with non-lame (healthy) conditions. Three 3D wireless orientation sensors were mounted on the sacrum of each horse to record their motion.
• The measurements focused on three types of movement: lateral bending (side-to-side movement), flexion-extension (forward and backward bending), and axial rotation (twisting motion).

Findings of the Study

• The results showed that the walk values were generally greater than trot values when measured using pin-mounted sensors in all types of movements.
• When the sensors were skin-mounted, the measurements for the trot motion was found to be greater in axial rotation whereas the lateral bending was less compared to the walk values.
• Poor correlation was found when comparing the average values for movements recorded by skin-mounted and pin-mounted sensors. This indicates the potential inaccuracies in measuring sacral and iliac movement using skin-mounted sensors.

Conclusions

• The research concluded that horses showed smaller movements while trotting when measured using bone-fixated sensors compared to when they were walking. The authors interpret this as increased muscular control in horses when they trot.
• The apparent increase in skin motion while trotting and the lack of correlation between skin- and bone-mounted sensors reveal inaccuracies when using skin-mounted sensors for measuring sacral and iliac movement in horses.
• The findings suggest a potential need for more accurate methods for measuring spinal movement in horses, which could further contribute to the understanding of equine biomechanics and possible applications in diagnosing and treating equine health conditions related to the spine.