Elephants' legs: Shakespeare was wrong
Friday, 22 Aug 2008 00:01
The elephant has long received a bad press about its legs, UK scientists claim
Science In Focus
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Elephant enthusiasts have poured water on claims dating back to William Shakespeare that the pachyderms' legs are inflexible.
New research shows an elephant's legs are capable of the same level of flexibility as those belonging to a horse.
The large land mammal has long received a bad press about its legs, UK scientists claim.
In Shakespeare's Troilus and Cressida, Ulysses theorises: "The elephant hath joints, but none for courtesy; his legs are legs for necessity, not for flexure."
Researchers from the London's Royal Veterinary College (RVC) set out to prove the Bard and countless others wrong by using Hollywood blockbuster 3D capture technology.
John Hutchinson from the RVC and his team turned the elephant enclosure at Colchester and Whipsnade Zoo into a film set.
After the team had stuck hemispheres covered in infrared reflecting tape to joints on the elephants' fore and hind limbs, the animals were happy to walk and run in front of the arc of infrared detecting cameras as the team filmed their steps at speeds ranging from 0.62 m/s to 4.92m/s.
"The big problem was keeping the markers in place, the little ones kept on pulling them off with their trunks," Mr Hutchison, writing in the Journal of Experimental Biology, said.
Having filmed animals ranging in size from 521 to 3,512kg, the team travelled to Thailand to film the athletic elite Thai racing elephants that easily outpaced the UK elephants at 6.8m/s.
The elephant's movements were converted into stick figures, and found that their legs are not as columnar as previously thought, with the shoulder, hip, knee and elbow joints flexing significantly.
As the elephants swung their front legs forward they also flicked their feet up, bending their wrists by more than 80°, to keep them clear of the ground.
Meanwhile, the elephants' ankles were far more rigid. Unable to bend the ankle as they swung their legs, the animals moved them out in an arc, to avoid dragging their hind feet along the ground.
However, it was a different matter when the team analysed their joints during the stance phase; the apparently rigid ankle was relatively spring-like, whilst the previously flexible wrist became rigid while supporting the animal's weight.
When the team compared the elephants' movements with those of horses, they found that the elephants' joints were almost as mobile as trotting horses'.
A comparison between Thai elephants and their more sluggish UK cousins showed their movements were essentially the same. Captivity had not modified the elephants' mobility range, just slowed them down a little.
"The [zoo]keepers were very pleased," Mr Hutchison added.