Oscar Pistorius = Daegu 2011 + London 2012 : experts say South Africa's 'blade runner' gains advantage from his technology

Four years after the Court of Arbitration for Sport cleared Oscar Pistorius to compete in able-bodied athletics, South Africa's "blade runner" yesterday qualified to run the 400m at next month's world athletics championships in Daegu, South Korea.

A double below-knee amputee almost from birth, Pistorius, 24, ran a personal best of 45.07sec to win in Lignano, Italy. His time betters the stiff IAAF entry mark of 45.25sec, which no Australian has clocked this year.

Pistorius' time would have won the Australian title in April by about 3m. So now, with intersex Caster Semenya to defend the women's 800m title captured two years ago in Berlin, and Pistorius to race in the men's 400m, the world championships are set to be overwhelmed by South Africa's controversial causes celebre.

It is not that Pistorius should not be cheered for his courage and persistence, but the scientists whose work convinced CAS judges to support him because he has "no significant advantage" through the technology of his carbon fibre limbs have changed their minds.

Exercise physiology professors Peter Weyand and Matthew Bundle provided the scientific proof which persuaded CAS to clear the Cheetah blades worn by Pistorius.

But they claim to have made their conclusions based on incomplete evidence at the time. They have since concluded - and published their findings in the Journal of Applied Physiology - that Pistoriusw' prosthetics provide a significant advantage. They calculate the artificial limbs take as much as 10 seconds off the 400m time he could have run had he been born with lower legs.

"We are pleased to be able to finally go public with conclusions that the publishing process has required us to keep confidential," Bundle and Weyand stated. "We recognised that the blades provide a major advantage as soon as we analysed the critical data."

The scientists have found Pistorius' blades enable him to reach speed while applying 20 per cent less ground force than an able-bodied sprinter.

He also has a stride rate advantage, turning his levers over "15.7 per cent more rapidly than five of the most recent former world record-holders in the 100m dash".

They further found that his blades "reduce the muscle forces Pistorius requires for sprinting to less than half of intact-limb levels".

With the command of his blades he now has, and the speed he can generate with the superb economy of energy, Pistorius could win a 400m medal in Daegu. Trinidad's Renny Quow won bronze in Berlin in 45.02sec. Pistorius' 45.07sec ranks him 15th fastest man in the world this year.

NBA: Yao Ming retires from basketball

Yao Ming has made it official Wednesday, telling a packed news conference in his hometown that a series of foot and leg injuries have forced him to retire from basketball.

"I will formally end my career," said Yao, the 7-fooot-6 center who became a household name in China before starting his NBA career with the Houston Rockets as the top draft pick in 2002.

Yao played eight seasons in the NBA, but missed 250 regular-season games over the past six years.

"Today is an important day for me and holds a special meaning for both my basketball career and my future," Yao said in comments translated into English. "I had to leave the court since I suffered a stress fracture in my left foot for the third time at the end of last year. My past six months were an agonizing wait. I had been thinking (about my future) over and over. Today I am announcing a personal decision, ending my career as a basketball player and officially retire. But one door is closing and another one is opening."

Houston general manager Daryl Morey attended Yao's farewell conference Wednesday, and NBA Commissioner David Stern sent a message via video link. Morey had to get permission from the NBA to be attend because the lockout prohibits contact with players.

"Yao Ming has been a transformational player and a testament to the globalization of our game," Stern said in a statement. "His dominant play and endearing demeanor along with his extensive humanitarian efforts have made him an international fan favorite and provided an extraordinary bridge between basketball fans in the United States and China."

Yao said he will return to work with his former Chinese team, the Shanghai Sharks, with the possibility of becoming general manager. He plans to continue his philanthropic work with his Yao Foundation.

Yao entered the conference room at a five-star hotel dressed in a dark suit, after the master of ceremonies led a count down to his arrival.

Yao's wife, Ye Li, and their young daughter, Yao Qinlei, and Yao's parents were in the room. Qinlei was dressed in a red qipao, a traditional Chinese dress. He later appeared with his family on the stage to the applause and cheers of the room.

He thanked his family, friends, coaches in China and in Houston and fellow competitors such as Shaquille O'Neal "for making me a better player".

"I will be always with you," Yao said. "Thank you."

Despite news of Yao's pending retirement being out for several weeks, the actual announcement was treated with the pomp that Yao's appearances in China bring. Media were asked to sign up weeks in advance for the conference and show up two hours early to pass through airport-style security checks.

The Grand Shanghai Ballroom was crammed at the back with dozens of television cameras and black-suited security men outnumbered the hundreds of media. China Central Television planned to carry five continuous hours of Yao coverage beginning at 1 p.m. local time, including 90 minutes live from the media conference.

Yao's contract expired after last season, and the Rockets said they were interested in re-signing him if he came back healthy. Yao said in April in China that his professional future depended on his recovery from a stress fracture in his left ankle.

Selected to the NBA All-Star team eight times, Yao averaged 19 points and 9.2 rebounds. More importantly, his impact expanded the NBA's influence in Asia into lucrative merchandise sales and TV ratings.

After his rookie season, Yao helped the Rockets reach the playoffs in the next two seasons.

Yao played in 77 games in the 2008-09 season, when Houston reach the second round of the playoffs for the first time since 1997.

But Yao broke his left foot in a playoff game against the Los Angeles Lakers, and underwent complex surgery that sidelined him for the entire 2009-10 season. He lasted only five games at the start of the 2010-11 season, before breaking his left ankle. He had surgery in January, and was lost again for the season.

Yao had played six years with the Chinese national team before joining the Rockets, and was already a star in his home country. He carried the Olympic torch through Tiananmen Square and his country's flag during the opening ceremonies at the Beijing Olympics in 2008. He also donated $2 million and set up a foundation to rebuild schools in the wake of the 2008 earthquake in Sichuan.