Effect of Perineural Anesthesia on the Centre of Pressure (COP) Path During Stance Phase at Trot in Sound Horses.
Authors: Hagen Jenny, Geburek Florian, Kathrinaki Vasiliki, Naem Mohamad Al, Roecken Michael, Hoffmann Johanna
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Researchers at this German institution sought to understand whether proprioceptive feedback from the equine foot influences pressure distribution patterns during weight-bearing, specifically by measuring centre of pressure (COP) trajectories through stance and breakover phases at trot. Ten clinically sound horses underwent pressure plate analysis of both forelimbs before and after palmar digital nerve blocks administered unilaterally and bilaterally, with COP mapping recorded from initial contact through mid-stance to toe-off. Remarkably, the location of initial contact, peak pressure during mid-stance, and breakover point remained unchanged following sensory denervation, and stride-to-stride variability in COP paths proved negligible regardless of anaesthetic status. These findings suggest that foot proprioception plays a minimal role in determining how the hoof distributes pressure during normal stance mechanics in sound horses, which has important implications for interpreting gait changes observed in clinical practice—particularly when nerve blocks are used therapeutically or diagnostically, as sudden alterations in movement patterns cannot be simply attributed to loss of proprioceptive input from the foot itself. This work underscores the complexity of lameness evaluation and suggests that gait changes following perineural anesthesia likely reflect pain relief rather than disrupted sensory feedback, warranting careful clinical correlation and further investigation into the neural mechanisms driving movement adjustments.
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Practical Takeaways
- •Gait changes observed after nerve blocks in horses should not be automatically attributed to altered foot pressure mechanics—investigate other neuromotor factors
- •In sound horses, the foot's pressure distribution pattern appears to be controlled by factors beyond immediate proprioceptive feedback, suggesting central or other peripheral control mechanisms
- •Use caution when interpreting acute lameness or gait changes following perineural anesthesia without further biomechanical investigation
Key Findings
- •Individual COP paths during stance phase showed high repeatability with no significant inter-stride variability in sound horses at trot
- •Unilateral or bilateral abaxial sesamoid nerve blocks did not affect location of initial contact, midstance COP, or breakover in sound horses
- •Short-term loss of sensory feedback from the foot via perineural anesthesia does not alter foot pressure distribution during stance phase at trot