WASHINGTON, Nov 18, 2009 (AFP) - The artificial legs of South African paralympic champion Oscar 'Blade Runner' Pistorius give him a clear advantage, taking at least 10 seconds off his 400-meter time, a US study said Wednesday.
'Pistorius's sprinting mechanics are anomalous, advantageous and directly attributable to how much lighter and springier his artificial limbs are,' wrote professor Peter Weyand, a co-author of the research.
'The blades enhance sprint running speeds by 15-30 percent,' said Weyand, a professor of physiology and biomechanics at Southern Methodist University in Texas.
Matthew Bundle, assistant professor of biomechanics at the University of Wyoming, said most of Pistorius's speed advantage could be explained by how quickly his lightweight limbs allow him to reposition his legs.
'At top speed, Oscar Pistorius repositions his limbs 15 percent more rapidly than six of the most recent world record holders in the 100 meter dash,' wrote Bundle, calling his limb repositioning times 'literally off the charts.'
The springy, lightweight, J-shaped limbs called 'Cheetahs' allow Pistorius to attain the same sprinting speeds with 20 percent less ground force than able-bodied runners, and reduce to less than half the muscle force required for sprinting, the researchers said.
Weyand and Bundle analyzed the lower limbs on which Pistorius raced to three gold medals at the Beijing Paralympics.
The Swiss-based Court of Arbitration for Sport in May last year lifted a ban on him competing in able-bodied track competitions.
The ban had been imposed by the International Amateur Athletics Federation (IAAF), which said Pistorius's limbs gave him an unfair advantage.
Pistorius missed out on a place on the South African team at the Beijing Olympics last year but hopes to qualify for the 2012 Games in London.