Effect of blindfolding on centre of pressure variables in healthy horses during quiet standing.
Authors: Clayton Hilary M, Nauwelaerts Sandra
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary: Visual Input and Postural Stability in Horses Postural balance in standing horses depends on integration of visual, vestibular and proprioceptive feedback, yet the relative contribution of vision to stability had not been quantified in equine subjects. Clayton and Nauwelaerts measured centre of pressure (COP) movements using synchronised force plates whilst 20 healthy horses stood quietly under both sighted and blindfolded conditions, recording three 60-second trials per condition and calculating stabilographic variables including COP amplitude, velocity and mean power frequency in both craniocaudal and mediolateral directions. Blindfolding significantly increased both the magnitude and within-trial variability of craniocaudal and mediolateral COP amplitudes and mediolateral COP velocity, whilst mean power frequency (a measure of oscillation speed) remained largely unaffected—indicating that vision primarily influences the *extent* of postural sway rather than its *rate*. These findings suggest that assessment of visual contribution to balance through COP analysis could enhance clinical evaluation of horses presenting with neurological conditions affecting proprioception or vestibular function, particularly as instability from neurological disease tends to worsen with loss of visual compensation. Farriers and veterinarians managing horses with suspected balance deficits might consider how visual input interacts with other sensory systems during diagnostic assessment, though further work is needed to establish whether blindfolded COP testing adds diagnostic value in clinical populations.
Read the full abstract on PubMed
Practical Takeaways
- •Blindfolding can be used as a clinical diagnostic tool to unmask balance deficits in horses with suspected neurological disease, similar to its diagnostic value in human neurology
- •Normal horses show increased postural sway when blindfolded; exaggerated responses may indicate vestibular or proprioceptive dysfunction that warrants further investigation
- •Stabilographic analysis of centre of pressure provides objective, quantifiable measures of balance that are more sensitive than visual observation of hooves, head and neck movements
Key Findings
- •Blindfolding increased craniocaudal and mediolateral centre of pressure amplitudes compared to sighted conditions in healthy standing horses
- •Within-trial variability of craniocaudal and mediolateral COP amplitudes and mediolateral COP velocity increased significantly when visual input was removed
- •Visual loss had greater effects on time-domain variables (amplitudes and velocities) than frequency-domain variables (mean power frequency)
- •Loss of visual input measurably affects postural stability in horses, with implications for neurological disease diagnosis