Maddison was barely audible when the Illawarra Mercury contacted him to check on his condition yesterday, with his breathing heavily laboured, as his left lung was still to be reinflated.

"Sorry, I can't really talk, I've still got a collapsed lung," was all Maddison could manage.

But the Kiama superstar appeared to be in good spirits this morning, posting a photo from his hospital bed with the caption: "Morning hubbly bubbly, get them lungs pumpin! Should be getting out tomorrow!"

The Kiama superstar was negotiating the stutters of the X Games course during a training session on Sunday when he went over the handlebars and crashed heavily into the dirt, the bike landing on top of him.

His mother Debbie also spoke to him briefly yesterday and is optimistic he will be back on his feet, if still a little sore, in time for his 31st birthday next week.

It is the second time in as many years Maddison has suffered injuries of this sort.

"It doesn't get any easier," his mother said yesterday.

"You hear he's hurt himself again and you just feel his pain.

"I can never bring myself to look at the photos of what he's done. I just want to concentrate on him getting better."

This is the downside to the breathtaking and highly dangerous life of one of the world's best daredevil stunt riders.

Doctors initially believed Maddison had broken his leg, but X-rays later revealed those injuries to be pre-existing.

"It doesn't surprise me, especially when he tends to hurt the same things," his mother said.

"It's hard to distinguish what's new and what's old.

"I'm not too worried about his leg, it's the ribs and the lung that I was really worried about.

"It was quite a relief to find out he had avoided any kind of head injury.

"He knows the drill now, he's just got to stay there and get better," she said.

Maddison's list of injuries is almost as long as the biography of spectacular jumps he's completed.

In 2009, he successfully leapt across the landmark London Tower Bridge and he's also conquered a replica of the Arc de Triomphe in Las Vegas, as well as numerous world record jumps.

The remarkable career has seen him take on the role of stunt double for movie star Daniel Craig in the film Skyfall, which will be released in October.

But it has come at some cost. Last year, Maddison suffered a compressed vertebrae in his back, while he missed the 2007 and 2009 X Games with a broken leg and then dislocated his shoulder.

Maddison had surgery to repair a ruptured disc in January and was back to full fitness during the Moto X speed and style competition in the United States.

"He was quite positive about bringing home a medal this time, that's the disappointment for him," his mother said.

"That's the highs and lows of what he does.

"He's been feeling fantastic, this is just another hiccup.

"But you can't keep a good man down."