Despite the controversy surrounding Oscar Pistorius' right to compete in the 2012 London Olympics, 'The Blade Runner' will be running in the individual men’s 400 m and 4 x 400 m relay on behalf of South Africa. He will also be competing in the Paralympic Games.

Like a cheetah

The carbon fibre composite prosthetic foot he wears is manufactured by Össur, a manufacturer of non-invasive orthopaedics headquartered in Iceland. Pistorius has been competing with the same Össur manufactured blades since 2004.

Össur’s Flex-Foot Cheetah is a J-shaped carbon composite prosthetic sprinting foot. It's used mainly by people like Pistorius with below-knee amputations, but is also suitable for some above-knee amputees. Össur’s design aims to capture the running characteristics of the cheetah, the world’s fastest land animal. It replicates the cat’s hind leg, whose foot extends and reaches out to paw at the ground while the large thigh muscles pull the body forward.

Carbon fibre technology

The Cheetah features proprietary carbon technology to efficiently store and release energy produced by the user while running. When the wearer is running, the prosthesis’ 'J' curve is compressed at impact, storing energy and absorbing high levels of stress that would otherwise be absorbed by the runner’s ankle, knee, hip and lower back. The J curve then returns back to its original shape, releasing the stored energy and propelling the runner forward.

Studies have shown that the Flex-Foot Cheetah can return around 90% of the energy stored in it. This is far less than a normal able-bodied foot and leg, which has been shown to return 249% of the stored energy.

The Flex-Foot Cheetah is designed to have more layers of carbon at higher stress points, such as the apex of the J curve, and less carbon where more flexibility is needed, such as the toe portion. There is no heel component. This ensures that the prosthetic foot’s reaction accurately mimics that of an able-bodied runner replicating both the stance and swing phases of running.

Typically, the spike plate of a sprinting shoe or the sole of an athletic shoe are applied to the foot’s carbon toe to provide traction and conformity to the running surface.

Controversy

So do these carbon fibre blades give Pistorius a competitive advantage over able-bodied athletes?

Pistorius' website states that Flex-Foot Cheetahs, which have been used by Paralympic athletes since 1996, have been scientifically proven not to give a net advantage over able-bodied athletes. In 2008 the Court of Arbitration for Sport ruled that Pistorius can legally compete in International Association of Athletics Federations (IAAF) athletics races wearing Össur Flex-Foot Cheetahs.

However, many still believe that disabled athletes who use prosthetic limbs should not be allowed to compete in 'able-bodied' races. 400-metre world record holder Michael Johnson is one person taking this position, saying that because we don’t know for sure whether Pistorius gets an advantage from the prosthetics he wears it is unfair to the able-bodied competitors. 

The debate is certain to continue and all eyes will be on Pistorius at London 2012.

What's your opinion? Do Pistorius' carbon fibre blades give him an unfair advantage or not?

One thing is certain though. This is some very impressive carbon fibre technology!