If Oscar Pistorius gets his way there will be a pair of ‘cheetahs’ entering competition in the 2008 Olympics in Beijing, China. Opposition to his dream is fierce, however. The cheetahs are thought to have an unfair advantage over normal competitors. Actually, these “cheetahs” are not the feline type, but rather the name given to a pair of j-shaped prosthesis Oscar will wear if he becomes the first amputee runner in the Olympic Games — Oscar, a.k.a., “The Fastest Thing on No Legs.”

The controversy over his desire to enter competition in the Olympics (he is a two-time medalist from the 2004 Paralympics) is heated by concern that he would have an unfair advantage — a testament to the progress made with limb prostheses in recent years…

Although prosthesis have been around for more than 2000 years — one of the earliest known dates back to 300 BC and was a copper-wood leg — only in recent years have they developed to the point where their function now approaches that of a normal limb. New materials such as thermal plastics and composites such as carbon fibre make the prosthesis lighter and stronger while the addition of electronic motors and microprocessors are providing enhanced functionality permitting ever more control and ultimately, more autonomy for those that require them. Attachment of the limb also improved and is now commonly done via vacuum technology that provides a suction cup-like connection. This breakthrough permitted limbs like artificial legs to remain in place even when running.

The myoelectric hand is an excellent example of the technological advance made in this area. This device is capable of responding to brain commands via a computer chip and sensors attached to muscles on the chest and back and can provide the dexterity and control needed to tie a shoelace, for example. This device has already been built upon to include a full arm as well and earlier this year Claudia Mitchell, a former US marine who lost her arm in a motorcycle accident, was able to benefit from this device. To use it, surgeons had to re-route the motor nerves that once controlled her arm into muscles in her chest and side. In this situation, if she tries to move her arm or hand, specific muscles in her chest or side will contract and a myoelectric sensor attached to the muscle detects the contraction and sends the appropriate message to the arm or hand. With this device she was able to regain some significant abilities, such as being able to cut up food at a pace four times faster than someone with a more traditional prosthesis.

A bionic foot and ankle was recently patented by the researchers at the Biomechatronics Lab at MIT that attempts to match the function of a normal foot during walking and over a variety of different terrain, such as stairs. The ankle contains a motor that controls the angle and force absorbed and released with each step. A similar device from Ossur called the Proprio Foot is already on the market and it touts the ability for users to place both feet behind their knees when getting up or sitting down into a chair (the most natural position) and when walking it automatically lifts the toes at the appropriate point in the step to ensure sufficient ground clearance and create a balanced gait. The same company also offers a bionic knee that interactively responds to changes in the walking speed, applied weight and terrain.

But what of Oscar Pistorius? The International Association of Athletics Federations has given the South African the green light to compete in 2008 reversing a decision earlier this year that banned any athlete from competing that would benefit from artificial help. But while the go ahead has been given, the scientific investigation into the technical advantages of his “cheetahs” continues. As long as this investigation shows that there is no technical advantage and more critically, if Oscar can qualify for entry, the world will have even more of a reason to watch the most spectacular sporting event on Earth come 2008.

Additional Information: Ossur –

Oscar Pistorius’s Web site

Michael Little works in analytical chemistry and has almost 20 years experience in the research based pharmaceutical industry. Michael resides in Laval, Quebec, with his wife and three children. Michael has written occasional science articles for GNN since 2007.


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