Experts bemoan humans' ineptness in depicting animals' gait
THURSDAY, Feb. 26 (HealthDay News) -- If you have a dog, you probably take it for a walk, at least now and then. But do you actually watch the dog walk? Or, more specifically, can you describe how your dog does it?
If not, you're apparently in good company.
Taxidermists, toy designers, artists and more frequently get it wrong, according to a study on the foot-fall pattern of dogs and other four-legged creatures that was published in Current Biology.
The pattern is formulaic, explained study author Gábor Horváth, a biophysicist at Lorand Eötvös University in Budapest, Hungary. And at a walk, he said, it never varies: The animal steps forward with the left hind leg, followed by the left foreleg, then the right hind leg followed by the right foreleg.
And they walk this way for a very good reason, he explained. Balance.
Three feet are always on the ground at once, creating a supporting triangle "for which the static stability is maximal," Horváth said. Any other pattern would be less stable, he said.
"It's not really complicated," said Dr. Bonnie V. Beaver, a veterinarian and professor in the department of small animal clinical sciences at the College of Veterinary Medicine & Biomedical Sciences at Texas A&M University.
It's also not a new finding. Yet those who in some way depict four-legged animals in motion get it wrong about 50 percent of the time, the study found.
Who cares, you might well ask?
The researchers say that toys or model animals might fall over less often if they were depicted with the correct foot-fall pattern. And museum displays and textbook illustrations just ought to get it right, they argue. But there's more.
"People have had an interest in [locomotion] for a long time," Beaver said. "Dog breeders look at how dogs gait in the show ring, and horse people study how the feet touch the ground in sequence and so on. It's something that people who work with animals as they move have had an interest with."
Yet for all the study and attention paid to quadruped locomotion, how fast they move has not progressed dramatically.
"If you look at running horses, for example, the times of the winners of the Kentucky Derby really haven't changed very much," Beaver said. "Humans have inched up by seconds, and we make a big deal about it. The same is true for horses. In spite of taking the very best and breeding the very best, it really hasn't changed it. That says there's a kind of a limit, and we're near the maximum."
Swimmers in special suits only manage to shave off tenths of a second.
But there are exceptions.
"Secretariat was special and blew many of the records out of the water," Beaver said. "They found the horse had a longer stride so he covered more ground for the same amount of motion and could do it just a little bit faster. I've seen sequences where he and his stablemate are running side by side with the same identical stride, and Secretariat covered a few more inches each time. Also, that horse had a larger heart so he could pump more blood."
Even without bionic-like body parts, humans might want to take a cue from the success of Secretariat's legendary stride and try to perfect their own gait.
Few people walk correctly, contend the writers of an article in the February issue of the Harvard Health Letter, who say the proper locomotive style is "head erect, back straight, arms bent, knees extending and flexing, and feet striking the ground with the heel and pushing off with the toes."
The National Institute of Diabetes and Digestive and Kidney Diseases has more on the benefits of walking for people.
SOURCES: Gábor Horváth, D.Sc., biophysicist, Lorand Eötvös University, Budapest, Hungary; Bonnie V. Beaver, D.V.M., professor, department of small animal clinical sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas; Jan. 27, 2009, Current Biology; February 2009, Harvard Health Letter
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