10 ways to reduce the risk of damaging these dynamic structures

Tendons connect muscle to bone via their tough, fibrous strands. Wherever animals have bones and muscles, they have these collagen-fiber structures. But tendons in horses’ legs are unique in that they store high levels of quick energy, which they release after each step, making them capable of phenomenal athletic efforts.

It’s a “brilliant” design that’s helped this rapid-reaction prey species outrun many of its predators across its evolutionary history, says Claire O’Brien, MRes, PgDip, BSc (Hons), FHEA, of the University of Limerick, in Ireland, previously a researcher at Aberystwyth University, in the U.K.

But the tradeoff for such a design is these weight-bearing tendons are especially prone to injury and reinjury, says Roger Smith, MA, VetMB, PhD, DEO, Dipl. ECVSMR, ECVS, FRCVS, professor of equine orthopedics at the U.K.’s Royal Veterinary College Hawkshead Campus, in Hatfield.

Both the deep digital flexor tendon (DDFT) and especially the superficial digital flexor tendon (SDFT) are at risk for damage, meaning months or years of time off work or even the end of a horse’s athletic career.

Ideally, we’d reduce horses’ risk of sustaining tendon damage altogether, our sources say. Here are 10 ways to help.

1. Understand biomechanics and “biothermics” of tendon function.

Tendons are viscoelastic structures, meaning they stretch, and their mechanical behavior changes depending on how far and frequently they’re stretched, Smith says. Basically, tendons efficiently provide energy when weight-bearing but break down when stretched beyond their limits.

The SDFT, for example, stretches up to 16% in high-impact situations such as jumping and galloping, Smith says.

O’Brien adds, “If you could just watch a video of a horse coming to a fence in slow-motion and see that last step before takeoff, you’d be absolutely shocked to see how much the distal limb drops down