In a post on this blog earlier this week, S Lepard wrote:
Bob Baffert was quoted as saying something along the line that he used to hate racing on synthetic surfaces until he learned to buy the type of physicals suited to synthetics. I would like to know your thoughts on the type of horse and biomechanics of racing on synthetics.
The subtext of this query is that racing on synthetics requires a different way of going or a different expression of racing ability than racing on either dirt or turf. From all the evidence I’ve gleaned to date, that is correct.
Undoubtedly, synthetic tracks stress the horse’s body in different ways than dirt or turf surfaces. Some of the differences are for the better, and some are not. Veterinarians and trainers have reported noteworthy declines in traumatic fractures, especially to the forelegs. But they also have reported increases in soft-tissue injuries, especially of the hindquarters.
Anyone who has walked across a synthetic track, or has ridden a horse on one, can immediately tell you some of the reasons for this. First, synthetics mute the concussion of impact. You can even hear the difference because there is no great thunder of hooves when horses are racing on synthetics. Second, synthetics deaden the forces of the stride in every respect.
The second point is the problem, I believe. If synthetics did nothing more than soften the impact of the horses’ legs during racing, it would be the most extraordinary racing invention in a long time. But deadening or dampening the forces of the stride creates some negative effects, as well.
Just a few days ago, I was showing a friend the training track at Keeneland, and as an observant man, he noticed that the Polytrack did not break away from his foot the way that sand would as he walked across the track surface. The synthetic stayed in place and was still quite soft to walk on.
Jockeys love this effect because synthetic tracks produce minimal kickback, even on the rainy days that once drenched riders with mud every time they rode. But the effect is not entirely good for a horse’s body.
One the effects of synthetic racing surfaces is the reduction in slide when a hoof strikes the surface. Just as my friend could feel the difference as he walked on the synthetic material, when a horse’s hoof strikes the track, the surface doesn’t slide away like sand and clay will. The slide on a dirt track allows the impact of the hoof strike to be stretched over time and distance, which is the benefit to the cushion of a dry dirt track, but with a synthetic track, the hoof really sticks in the track surface. That can be harmful to the horse, but the harm depends on the horse’s stride and timing.
When a horse is not tired, the reaction between the horse’s hoof and the track isn’t so much of a problem. The deadening nature of the synthetic track tends to make it more tiring (not exactly more slow), and the result is that a horse tires, its action becomes less efficient, and it is more likely to damage any mechanical shortcomings in its design.
Every horse has mechanical shortcomings, except possibly Secretariat. This is not the same thing as saying that a horse is unsound or is a bad horse. For instance, if a horse was racing soundly on dirt, then switched to a synthetic track and developed heat in one or more suspensories, there is some issue with the way the horse is moving over the track, and the suspensory is being unduly strained because of that.
The problem might be as simple as a difference in shoeing, which can be changed quickly. Or it might be as complicated as the horse’s stride pattern and cadence, which can be changed only a bit. The latter finding would tell the owner and trainer that synthetic surfaces are not suitable for the horse, and that is an absolute certainty for some horses.
Just as there are some horses who race notably better on synthetic (Blue Grass Stakes winner Dominican comes to mind), others do not prosper on it, and more still are benefited in some ways, not in others.
Other considerations regarding synthetic tracks include the grip it provides for hindquarter propulsion and the similarities and differences between synthetic and turf. These will come up in subsequent posts.