Elephants' legs propel them around just like a 4x4, study finds

By Daily Mail Reporter

All terrain: Scientists have discovered that elephants are able to accelerate and brake with all four of their legs independently


Elephants have legs that work just like the wheels of a Land Rover, scientists have found.

The elephant's unique 'four-leg-drive' systems means power and braking is applied independently to each limb.

All other quadrupeds are thought to have 'rear-leg-drive', which means they tend to accelerate with their hind limbs while using their forelegs more for braking

Dr John Hutchinson, who lead the study at the Royal Veterinary College in London, said: 'We have developed some new techniques for looking at animals movements that may change the way we view the locomotion of other animals.

'We have shown that elephant legs function in very strange and probably unique ways.
'We even overturned some of our own previous ideas about elephants, which is always initially disheartening but ultimately exhilarating for a scientist.

'Our measurements have also provided basic data that will be useful in clinical studies of elephants, such as common lameness problems.'

Measurements of forces on the animals' legs at walking and running speeds showed that each limb was used for both accelerating and braking.

Elephants' legs were also shown to be slightly compliant or 'bouncy', especially when running at faster speeds.


Four-wheel-drive: Reflective markers were put on the elephants and they were recorded with infra-red cameras to see what their muscles did as they moved


Experts had previously assumed that elephants would need rigid 'pillar-like' legs to support their weight.

Bounciness made their legs two or three times less mechanically efficient than expected, putting them on a par with humans.

Just as in humans, muscle forces in elephants have to increase as their limbs become more flexed.

Consequently, running is 50 per cent more costly than walking, which is why elephants are slower than many other animals.

The study, published in the Proceedings of the National Academy of Sciences journal, said: 'Surprisingly, elephants use their forelimbs and hind limbs in similar braking and propulsive roles, not dividing these functions among limbs as was previously assumed or as in other quadrupeds.

'Thus, their limb function is analogous to four-wheel-drive vehicles.

'To achieve the observed limb compliance and low peak forces, elephants synchronise their limb dynamics in the vertical direction, but incur considerable mechanical costs from limbs working against each other horizontally.'

The researchers analysed the movements of six juvenile Asian elephants using an advanced 3D motion-capture technique.

Reflective markers placed at strategic points on the elephants' bodies were filmed by seven infra-red cameras and their changes in position fed into a computer.

The elephants were ridden or guided by their 'mahouts' across their whole range of speeds along a walkway rigged with force-sensitive platforms.


source: dailymail