Equine digital tendons show breed-specific differences in their mechanical properties that may relate to athletic ability and predisposition to injury.
Authors: Verkade M E, Back W, Birch H L
Journal: Equine veterinary journal
Summary
# Editorial Summary Selective breeding has fundamentally shaped equine locomotor traits, with Thoroughbreds developed for high-speed racing and warmbloods and Friesians selected for athletic movement and presence. Verkade and colleagues examined whether these functional demands have produced breed-specific differences in tendon mechanics by harvesting superficial digital flexor tendons (SDFT) and common digital extensor tendons (CDET) from eight Thoroughbreds, twelve warmbloods and twelve Friesians (aged 3–12 years), then testing their load capacity, elastic modulus, strain tolerance and stress resistance. Warmblood SDFTs demonstrated substantially lower elastic modulus than Thoroughbred equivalents whilst tolerating significantly higher loads and strain before failure—properties that align with the explosive, extravagant movement required in sport disciplines rather than the sustained high-speed effort of racing. CDET properties remained consistent across all three breeds, and both tendon types showed the expected mechanical relationships, with CDETs exhibiting higher stiffness than SDFTs. These findings suggest that breed-specific SDFT mechanics directly reflect selective pressure for different athletic demands and may indicate inherent performance potential or, conversely, predisposition to injury—a consideration particularly relevant when prescribing rehabilitation protocols, conditioning programmes and farriery interventions across different equine populations. The authors acknowledge that unknown exercise histories and wide age variation limit absolute comparisons, but this work opens discussion around whether breeding-associated tendon properties warrant individualised management strategies based on breed-typical biomechanics.
Read the full abstract on PubMed
Practical Takeaways
- •Different horse breeds have inherently different tendon properties; Thoroughbreds may be predisposed to different injury patterns than Warmbloods due to stiffer but less extensible superficial digital flexor tendons
- •Understanding breed-specific tendon biomechanics can inform realistic expectations for athletic capacity and injury prevention strategies tailored to breed type
- •Exercise conditioning and discipline selection should account for breed-specific tendon properties, as mechanical advantages and vulnerabilities vary systematically between racing and sport horse breeds
Key Findings
- •Superficial digital flexor tendons (SDFT) from Warmbloods showed significantly lower elastic modulus compared to Thoroughbreds, failing at higher strain and load
- •Common digital extensor tendons (CDET) showed no significant mechanical property differences between breeds but consistently demonstrated higher elastic modulus and stress tolerance than SDFT
- •Breed-specific differences in SDFT mechanical properties correlate with selection for high-speed locomotion (Thoroughbreds) versus extravagant elastic gait (Friesians and Warmbloods)
- •Mode of failure differed between breeds, particularly in Friesian horses, suggesting breed-specific structural or compositional tendon variations