Single inertial measurement units attached to the back of a horse can detect postural sway, researchers report.
Postural sway is the subtle sway present during a quiet stance. It forms part of the body’s ability to balance in any posture or activity.
In humans, postural sway is often used to quantify human postural control, balance, injury, and neurological problems.
However, there is considerably less research investigating the value of assessing it in horses.
Sonja Egan and her colleagues, writing in the journal Sensors, noted that much of the existing equine postural sway research used force or pressure plates to examine the centre of pressure, inferring changes at the centre of mass.
For their research, the study team at University College Dublin explored the feasibility of capturing useful postural sway data in an applied setting using a much simpler method — the use of a single inertial measurement unit fixed to the withers.
The researchers described their experiment in which seven horses had a single sensor mounted on the back. Temporary lameness in both front legs was induced to assess its influence on postural sway.
They detected significant changes in the nature of the horses’ postural sway when lame. There was a greater amplitude of displacement in the craniocaudal (front to back) versus the mediolateral (side to side) direction.
They said the significant reduction in mediolateral displacement during the acute inflammation period during the horse’s lameness, alongside greater overall craniocaudal displacement, may be a compensatory behaviour for bilateral lameness.
Their research, they said, demonstrated the basic capabilities of postural sway monitoring using a single inertial sensor.
The next steps in field-based monitoring should work toward understanding more clearly the natural day-to-day biological variability of postural sway in equines, they said.
Further research could also examine a wider range of postural sway measures, and investigate sensor-video integration capabilities to enable unsupervised monitoring.
“Additionally, the onset and recovery of bilateral lameness versus unilateral lameness should be explored with respect to postural sway.
“This could potentially uncover further insights that could distinguish complex lameness and be applied in longitudinal monitoring paradigms to enable early intervention and recovery.”
The study team comprised Egan, Pieter Brama, Cathy Goulding, David McKeown, Clodagh Kearney and Denise McGrath.
Egan, S.; Brama, P.A.J.; Goulding, C.; McKeown, D.; Kearney, C.M.; McGrath, D. The Feasibility of Equine Field-Based Postural Sway Analysis Using a Single Inertial Sensor. Sensors 2021, 21, 1286. https://doi.org/10.3390/s21041286