Friday, November 03, 2006

French Researchers Study the Egg Bar Shoe

The fashionable use of the egg-bar shoe on performance may have peaked, but arguments over how and if the shoe helps performance horses or hurts them will go on and on and on.

Professor Jean-Marie Denoix of France has long been a stickler about the use of egg bars depending on if the horse is laid up or competing and, if competing or turned out, what surface the horse is working on.

We now have a new report from the vet school at Alfort in Paris, conducted by Denoix, with Henry Chateau and Christine Degueurce. They took the egg bar out of the hard force-plate track, which is how the shoe was tested by Alan Wilson's Motion and Locomotion Laboratory at the Royal Veterinary College in England. The French group tested it in sand.

Alas, the report does not specify if steel or aluminum was used, and what the thickness and width of the bar was. We will try to obtain that information. It is also not known if they measured both front and hind effects of egg bars. The data published is only on the front feet.

They used four sound horses and found that, compared to normal shoes, the heels really did sink less into the sand with the egg bars and that the horses' heels were raised at mid-stance phase, compared to plain shoes. Maximal flexion of the coffin and pastern joints was increased and extension of the coffin joint at heel-off (aka "breakover") was reduced.

In three-dimensional analysis, the egg bar affected the medial quarter's sinking into the ground.

Based on these findings, Denoix's group felt justified in recommending egg bar shoes for horses working in soft footing who might benefit from these changes in joint angles or who would work better moving more "over" than "into" soft footing.