Research paper indicates performance-relevant differences in racehorse tendons

The research team comprising UCL’s Helen Birch, Professor in Skeletal Tissue Dynamics at UCL’s Department of Orthopaedics and Musculoskeletal Science, Marlies Verkade, Equine Veterinary Surgeon and Willem Back, Professor in the Department of Equine Sciences, Faculty of Veterinary Medicine at Utrecht University found that Thoroughbred racehorses and horses used for other disciplines such as dressage and showjumping showed differences in tendon properties that were breed-specific.

Professor Helen Birch commented “The superficial digital tendon in the horse behaves like a spring and makes a significant contribution to the efficiency of locomotion. We found differences in the spring-like properties of the Superficial Digital Flexor Tendon suggesting that this tendon is highly tuned for ability in different gaits – likely due to selective breeding.  This is an exciting piece of research since it might predict winning potential and susceptibility to injury. Our findings also potentially relate to humans especially if exercise and training can enhance the differences.”

The aim of this study was to compare the biomechanical properties of tendons with different functions between equine breeds traditionally selected for racing (Thoroughbred) or sports such as dressage and show jumping (Friesian and Warmblood horses). This study used ex-vivo tendons and compared the mechanical properties of the energy-storing Superficial Digital Flexor Tendon, a very common site of injury and the rarely injured, non-energy storing Common Digital Extensor Tendon.

The Superficial Digital Flexor Tendon from Thoroughbred horses had a significantly higher elastic modulus than Warmblood horses demonstrating a ‘stiffer spring’ while the tendon failed at a higher strain in Warmblood horses demonstrating a greater ability to extend. The mechanical properties of the positional Common Digital Extensor Tendon did not differ between breeds. Interestingly, the mode of tendon failure also differed between breeds, suggesting a difference in the tissue structure.

The conclusions of this study show, for the first time, that mechanical properties of the Superficial Digital Flexor Tendon differ between breeds. These properties are likely to be related to selection for high‐speed versus an extravagant elastic gait and may be an important indicator of performance ability.

Read more about the equine study here https://onlinelibrary.wiley.com/journal/20423306

Photo credit: Keith Luke