The Feasibility of Equine Field-Based Postural Sway Analysis Using a Single Inertial Sensor
Authors: Sonja Egan, P. Brama, Cathy Goulding, David J. McKeown, C. Kearney, Denise McGrath
Journal: Sensors (Basel, Switzerland)
Summary
# Editorial Summary: Equine Postural Sway Analysis Using Wearable Sensors Postural sway measurement is well established in human medicine for detecting balance deficits and neurological dysfunction, yet its application in equine practice remains limited, largely because existing research relies on force plates that measure ground reaction forces rather than direct assessment of the horse's centre of mass movement. Egan and colleagues addressed this gap by attaching an inertial measurement unit (IMU) to the withers of seven horses and tracking postural displacement over seven days following lipopolysaccharide-induced transient bilateral lameness, validating whether field-based IMU analysis could detect movement compensations associated with acute inflammation. The researchers identified a significant reduction in mediolateral (side-to-side) sway displacement between 4–12 hours and 168 hours post-induction, alongside greater craniocaudal (fore-aft) displacement throughout, suggesting that acutely lame horses restrict lateral movement whilst increasing front-to-back postural adjustments as a compensatory strategy. Systemic markers (total protein, white blood cell count, and carpal circumference changes) confirmed the inflammatory response and recovery trajectory. This work opens practical possibilities for farriers, vets, and physiotherapists to objectively quantify postural control changes in the field using lightweight wearable technology, potentially offering an early indicator of lameness or musculoskeletal dysfunction before overt gait abnormalities become apparent, though larger validation studies are needed before routine clinical application.
Read the full abstract on PubMed
Practical Takeaways
- •A single IMU sensor at the withers can feasibly detect postural changes related to lameness in working conditions—offering a portable alternative to laboratory-based force plates
- •Horses reduce side-to-side sway when acutely lame bilaterally, which could help farriers and vets identify when lameness is affecting balance and proprioception
- •This non-invasive monitoring method may support objective assessment of recovery during treatment, though field validation on naturally lame horses is still needed
Key Findings
- •Mediolateral postural sway displacement significantly decreased during acute inflammation phase (4-12h) compared to recovery phase (168h)
- •Craniocaudal displacement was greater than mediolateral displacement overall, suggesting directional compensation pattern
- •Single withers-mounted IMU successfully detected postural changes associated with induced bilateral lameness in field conditions
- •Reduced mediolateral sway during acute phase appears to represent compensatory stabilization behavior in response to bilateral lameness