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Articles & Information
FROM THE HOOFCARE & LAMENESS ARCHIVES Virtual Reality? Hoof Balance Study at Texas A&M This article was published in Hoofcare & Lameness in 1995. Dr. David Hood of Texas A&M spoke eloquently on the balance controversy at the AFA Convention. He pointed out: "The horse's conformation allows peak mechanical stability. For every horse, there is a conformation that maximizes performance. The most mechanically sound foot is not necessarily the most athletic foot." Dr. Hood is working on a project tentatively titled "Conformational Symmetry of the Equine Digit", in which he will be evaluating breed types and the differences in people's perceptions of what proper balance is. Dr. Hood worked on 50 horses that had not been shod or trimmed in over a year. Using robotics, he prepared a computer analysis of each foot by tracing, or "mapping" the hoof wall. The resulting model on a computer screen looks like a diamond-mesh wire fence grid. He located what he called "the centroid axis" on each foot, around which the perimeter of the foot moves. He then compared normally and abnormally conformed feet rotating around the axis. The area volume of the foot was evaluated from the coronary band to the ground by change in diameter. Dr. Hood's findings include: 1) No foot was perfectly symmetrical. 2) Medial-lateral shifting was random. 3) Lateral shifting exceeded medial shifting. 4) Average dorsal toe angle for front feet was 53.3; hind feet 56.83. 5) Planar displacement was random. 6) There was a constant 10 percent increase in area per centimeter of length until the bearing surface was reached, where the area decreased. 7) Poor correlations can be drawn between dorsal toe angle and the area of the foot. In a second study, Hood studied the loading patterns in a normal standing horse by placing scales under each foot. He recorded that horses shift their weight constantly from side to side, left to right to left, but there is also a shift in diagonal weightbearing while standing. Hood said that he felt that this sort of "low grade pressure loading" while standing had an important effect overall on the horse. A horse may shift its weight over 100 times per hour. "You can't get a horse to stand still!" he said, half in jest. While standing for five minutes, an average horse bore
its weight 28% on each of its front feet, and 22% on each
hind foot. In a similar study, he recorded that laminitic
horses shift constantly from left to right but that they
"favor" one front foot over the other, and
while they still have the same 28:22 break between front
and hind, they may bear weight longer on one front foot
before shifting to the other front foot, and bear weight
on that front A natural question would follow: Do horses as a rule demonstrate preference between left and right? Dr. Hood feels that they definitely prefer one side or the other. This article originally appeared in Hoofcare & Lameness: The Journal of Equine Foot Science and is available for your personal use only. Re-publication is prohibited without the express written permission of Hoofcare & Lameness. Detailed information on this and many other hoofcare topics can be found in Hoofcare & Lameness publisher Fran Jurga's award-winning guide to hoofcare, "Understanding the Equine Foot". For more information, or to order, click here Back to the articles table of contents Write to H&L: PO Box 6600, Gloucester, MA 01930. Tel 978 281 3222; fax 978 283 8775. Email webinquiry@hoofcare.com. Internet http://www.hoofcare.com. © 1998
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