While the media attributes Liu Xiang's triumph at the IAAF Diamond League Shanghai leg to his newly-modified, seven-step start, an athletics expert claims the effect of Liu's new move has been exaggerated.

Wu Wenqiang, professor of the athletics department at the Beijing Sport University (BSU), claimed Liu's fine performance at the Shanghai race was due to his overall smooth form, rather than the advantage of saving a step.

"Running with eight or seven steps before reaching the first hurdle is actually not so decisive for elite athletes such as Liu," Wu told China Daily on Monday after witnessing him win the race in 13.07 seconds, the year's best time, on Sunday night.

According to Wu, finishing the 13.72-meter distance from the start line to the first hurdle with seven steps, instead of eight, was not a big difference.

Wu also stressed the muscle power needed for such a change was not as difficult as most people imagine.

"Physically, it (the change) is not so demanding."

However, Wu said the mental adaptation was huge.

"Liu has to start with his left foot in front, this is the key obstacle for him. Such a change of habit might upset his paces during sprinting to the first hurdle and affect his feeling of the first attack," said Wu, who used to be a professional hurdler at BSU.

"Liu needs time to get used to that change and has to maintain the frequency of his pace. If his pace slows down due to a larger stride, the advantage of the saved step will be erased," said Wu.

Still not fully recovered from the Achilles' tendon injury, which forced him to pull out of the 2008 Beijing Olympics, Liu's change of stride has raised concerns about the pressure on his right heel, which was surgically repaired.

However, Wu said the change affects his leg muscles more than his heels.

"Liu's leg-muscle power has been growing steadily together with other parts of his body. That balance should make him safe from another potential injury," said Wu.