London, Feb 12 (Inditop.com) The sheer size of pachyderms makes it impossible for them to bounce up in the air at high speeds. So how do high-speed elephants move: do they run or walk?

At a first glance, fast-moving elephants look as if they are walking, according to John Hutchinson from the Royal Veterinary College, UK.

But closer analysis of elephant footfall patterns by Hutchinson suggested that speedy elephants’ front legs walk while their hind legs may trot.

Norman Heglund from the Universite catholique de Louvain, Belgium, realised that the only way to resolve the conundrum was to measure the immense forces exerted on the animals by the ground as they move.

Heglund had to construct and calibrate an eight metre long, elephant-sized force platform from sixteen square metre force plates.

Crating the 300 kg force plates, cameras and computers in Belgium and shipping the equipment to the Thai Elephant Conservation Centre in Lampang, Thailand, Heglund, Joakim Genin, Patrick Willems, Giovanni Cavagna and Richard Lair built a reinforced concrete foundation and assembled the force platform ready to measure the enormous ground reaction forces generated by the animals.

Encouraged to move by their mahouts, 34 elephants ranging from an 870 kg baby up to a four-tonne adult moved over the force platform at speeds ranging from a 0.38 metres per second stroll to a 4.97 metres per second charge.

Based on the force measurements, the Belgian team was able to reconstruct the movement of each animal’s centre of mass and found that the elephant’s movements are extremely economical.

Heglund explains that the elephant’s cost of transport is low because the animal’s step frequency is higher than expected and they improve their stability by keeping an average of two feet on the ground even at high speeds, and three at lower speeds.

Combining these approaches, the elephant’s centre of mass bounces less than other animals’, reducing the giant’s cost of transport, said a release of the Royal Veterinary College.

The findings were published in the Friday issue of The Journal of Experimental Biology.