Synthetic track shows ability to reduce TB injuries

Researchers at the University of California, Davis, conducted a study to clarify the relationship between racetrack surfaces and specific effects on hoof acceleration and ground reaction forces (impact).

The study team, comprising veterinary orthopaedic specialists, biomedical engineers and mechanical engineers, set about measuring hoof acceleration, ground reaction forces and horse speed on dirt, synthetic and turf surfaces at the Keeneland Racecourse at Lexington, Kentucky.

Three three-year-old fillies, all checked for clinical soundness, wore an acceleration measurement device and a force-measuring shoe, information from which was recorded. The horses were walked, trotted and cantered in each phase of the experiment on each surface.

"Horse speed was limited to trot and canter to minimise fatigue during data collection," the researchers said in a report on their findings.

"The synthetic surface had the lowest values for most peak acceleration and mean vibration variables.

"The synthetic surface maximum acceleration during the hoof landing phase of stride was 81 per cent of the dirt surface maximum and 66 per cent of the turf surface maximum.

"Hoof forces contribute to forces incurred by bones, joints, tendons and ligaments of the equine forelimbs," they said.

"The synthetic surface also had the lowest peak ground reaction forces and load rate.

"Turf surfaces had the highest landing decelerations, probably due to the digging in of the hoof when landing and pushing off."

The authors said that only forelimbs were evaluated, and at speeds significantly slower than race speed.

"Although the results may not be identical at racing speeds, it is reasonable to expect that trends will be similar."

Hoof accelerations, ground reaction forces, and horse speed were measured on dirt, turf and synthetic surfaces at Keeneland Racecourse in Lexington, Kentucky. Instrumented horses were walked, trotted and cantered through the data collection corridor during three to four trials each of trot and canter.

They noted that, given the differences in footing materials, weather and track maintenance at different courses, "extending the results of this study to encompass all synthetic track surfaces should be done with caution".

"We are just scratching the surface with this study, but the comparative results results do look promising ..."

The synthetic track used for the study was a proprietary mixture of wax-coated silica sand, polypropylene fibre and recycled rubber.

The authors continued: "The development of standards for race surface materials is now needed to ensure consistency among racetracks, optimise horse performance and minimise risk for injury."

The study was undertaken by Jacob Setterbo, Tanya Garcia, Ian Campbell, Jennifer Reese, Jessica Morgan, Sun Kim, Mont Hubbard and Susan Stower.