Li Tao is struck by a taxi traveling at 30 km per hour, bounces over the roof and tumbles to the ground.

It may look like a horrific road accident, but Li is actually working, and this is the eighth time he has been hit in one morning.

He is just one of the unsung heroes of the big screen who often risk life and limb undertaking dangerous acts to give Chinese movies greater visual impact.

While "Chinawood" is undergoing a boom and the pay for actors has rocketed, the wages for Chinese stunt performers has dwindled due to the fierce competition for daredevil roles.

Stunt doubles used to be paid around 400 yuan ($63) a day, but lately they have seen the amount tumble to 200 yuan.

Their work is often dangerous - fighting, dodging explosions or running into cars - but it is all in a day's work for those who get a thrill from a high-risk job with little pay.

Li Tao, along with Cao Xu, Meng Mingang and Wang Meiying, are all stunt performers on the movie Shou Zhu Ren (The Guardians), which was filmed in Tianjin in December.

The stunts in the suspense thriller are the work of action director Zhao Zhenhua, who is a kungfu expert and played the stunt double for Nicolas Tse in the film A Man Called Hero in 1998.

Onset, he is demanding, carefully choreographing the scene with stunt performers and camera operators to achieve the most realistic shots.

But even onlookers recoil in horror as Li throws himself in front a taxi for the eighth time.

"One man can't get knocked down and fall like this, even if he is trained in kungfu," one bystander told a local newspaper.

Once again, Li steps out in the road, gets struck by the pale blue taxi and rolls over the roof, crashing to the ground.

This time, Li is hurt. But it's a minor injury to his finger, and the young stunt performer tells everyone, "It's fine. It's fine."

But the action director, who affectionately calls his performers his "brothers", is not so convinced.

"My brothers always say 'it's fine' whatever they've been through," Zhao says.

"But how is it possible to be fine after getting hit by a car and falling eight times. I used to be a stunt performer, and I know if it hurts or not."

And he has every reason to be concerned.

Li once broke a rib while filming an explosion scene for a movie and had trouble breathing for six months.

Cao Xu, another stunt performer working on the movie, was hospitalized after jumping from a building for a scene in another movie. He misjudged the jump and went spiraling to the floor headfirst. After regaining consciousness, he discovered it was only the quick thinking of his friends who moved the safety cushion that stopped him from breaking his neck.

And it's not just men who risk their lives to give action scenes an authentic feel. Women stunt performers are in great demand in China.

Wang Meiying started learning kungfu at the tender age of 6 and only graduated from Tianjin University of Technology in 2010 but is already booked out for most of the year.

She has one scene in Shou Zhu Ren that involves falling down stairs. It takes five takes, as the director insists on capturing her head banging in two specific spots during the fall. In the final cut, her painstaking scene will last seconds and most viewers will be unaware a stunt double was used.

"There are only a few women who know kungfu, and men cannot do the stunts as gently and elegantly as women," Wang explains.

"Small men can play some simple stunts for an actress. But complicated ones still need women stunt performers."

Wang also worked as an action double in Zhang Yimou's latest film, The Flowers Of War.

She is one of many who hope to find fame and fortune in the movie industry but are acutely aware the job has no long-term benefits.

As Zhao puts it: "A stunt performer must find other ways to make a living, as being beaten up and knocked down is a job for the young."