Relationships between exercise capacity and front hoof longitudinal balance in horses
Authors: Tacchio G, Davies HMS, Morgante M, Bernardini D
Journal: Equine and Comparative Exercise Physiology
Summary
Longitudinal hoof balance—the angle and leverage created by the dorsal and palmar cortices of the hoof—has long been suspected to influence locomotor efficiency, yet direct evidence linking it to exercise capacity remained absent until this investigation. Tacchio and colleagues used two complementary approaches: unshod horses performed incremental speed tests with lactate and stride metrics correlated against naturally occurring hoof balance parameters, then the same cohort underwent selective toe-length alterations via shoeing whilst maintaining consistent foot angle and ground clearance. In unshod horses, blood lactate at 10 m/s and total run time showed significant associations with dorsal cortex angle (mean 50°), palmar cortex angle (mean 29.6°) and breakover indices—measurements expressing the relationship between toe position and the centre of rotation of the distal interphalangeal joint. Shortening the toe without changing foot angle produced measurable benefits primarily in horses with dorsal cortex angles exceeding 45°, reducing lactate accumulation at 6 m/s and lengthening stride at working speeds, though the authors appropriately caution that hoof balance parameters themselves may reflect deeper conformational issues rather than being independent mechanical variables. These findings suggest that routine assessment of hoof angle alone may miss opportunities to optimise exercise economy through subtle adjustments to toe length, particularly in horses displaying steeper dorsal cortex angles—a nuance with direct implications for farriers managing performance horses.
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Practical Takeaways
- •Horses with steeper hoof angles (higher DC° and PC°) show reduced exercise capacity; farriers should consider these angles when addressing performance issues
- •Shortening toe length may benefit horses with steep dorsal cortex angles (>45°) by reducing lactate accumulation at moderate speeds and improving stride mechanics
- •Hoof balance is one factor among many affecting performance; assessment should consider overall conformation and physiological status alongside hoof geometry
Key Findings
- •Blood lactate at 10 m/s was significantly associated with dorsal cortex angle (DC°) and palmar cortex angle (PC°), with higher exercise capacity related to lower angles
- •Run time was significantly associated with breakover indices, suggesting breakover geometry influences exercise endurance
- •Decreasing toe length without altering foot angle reduced lactate levels at 6 m/s in horses with DC° >45° and increased stride length by 0.01-0.112 m
- •Hoof balance alterations had modest effects on exercise capacity, potentially confounded by other physiological and conformation factors