Linear elastic and hyperelastic studies of equine hoof mechanical response at different hydration levels.
Authors: Akbari Shahkhosravi, Gohari, Komeili, Burvill, Davies
Journal: Journal of the mechanical behavior of biomedical materials
Summary
Accurately modelling equine hoof biomechanics requires material models that account for the hoof wall's genuinely nonlinear stress-strain behaviour and its sensitivity to moisture content, yet most finite element studies have relied on oversimplified linear elastic assumptions. Akbari Shahkhosravi and colleagues compared linear elastic against three hyperelastic material models (Mooney-Rivlin, Neo-Hookean, and Marlow) using both isolated tissue specimens and full three-dimensional hoof models derived from CT scans, incorporating hydration levels ranging from completely dry (0%) to fully saturated (100%). The Marlow hyperelastic model demonstrated substantially superior accuracy across a wide range of strains compared to linear elastic and other hyperelastic formulations, particularly when predicting the hoof's actual mechanical response. When simulating trotting and standing gaits at varying hydration levels, increased moisture content significantly elevated tissue strains by reducing wall stiffness—a finding with direct relevance to seasonal and climate-related hoof problems. The stress concentrations identified in quarter regions and near the coronet band correlated with clinically observed crack and fracture patterns, suggesting that finite element predictions using appropriate material models may help explain why certain anatomical sites are predisposed to injury, and offering physiotherapists and farriers better evidence for targeted intervention strategies based on environmental and locomotor conditions.
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Practical Takeaways
- •Environmental humidity significantly affects hoof wall mechanical properties—wet conditions increase tissue strain and stress concentration, potentially explaining seasonal variations in hoof cracks and fractures
- •High-stress zones are consistently located in the quarters and coronet region, suggesting these areas warrant particular attention in farriery management and hoof care protocols
- •Linear elastic models underestimate actual hoof wall behavior; understanding nonlinear material response helps explain why some horses develop problems despite seemingly normal management
Key Findings
- •Marlow hyperelastic model predicted hoof wall stress-strain behavior more accurately than linear elastic and other hyperelastic models across wide strain ranges
- •Minimum principal strain in hoof wall remained under 2% across different hydration levels and gait conditions (trotting and standing)
- •Higher hydration levels (0%, 53%, 75%, 100%) significantly increased strains by decreasing tissue stiffness
- •Maximum von Mises stress concentrated in quarter regions and near coronet, correlating with typical locations of physiological cracks and fractures