Macdonald could not feel anything from the waist down.
But three years later, he is riding again at the elite level.
"The journey to here has been hard.
"It's not easy breaking your back and learning to walk again."
That was just one aspect of the recovery process, which proved to be a long and challenging. His first competitive ride was just over a year after the accident.
"But I'm here racing my bike again, and couldn't think of anything better to be doing."
He said it had been his job ever since leaving school, and he did not know anything else.
There was one goal: to ride his bike again.
"I was pretty driven to do that. I guess it paid off and got me here again."
This year, he said it would be nice to do as he did last year, but "we'll see".
He said the weather would not impact the event racing as much as others like slopestyle, but said the wet ground might work in his favour.
"The headwind might cause some problems... it seems like wherever a mountain bike event goes, the weather follows, and you never have a solid week of nice weather."
Macdonald said the gate start would be key, along with keeping up momentum.
"We'll just chip away at each heat race and hopefully make it to the final."
This year was his seventh time competing in the event.
"Pretty much every year it's been here, I've been here."
Crankworx was something special, he said, and was always a good time.
Locals were given free entry on Wednesday and Thursday, and Rotorua resident Carl Chadwick headed down yesterday with his family.
"We've been here six years and [have] not come, so thought we'd give it a go today."
He and his partner and two children had spent some time wandering around the event village and finished off with some food, which he said was good.
Mark Silk had travelled from Masterton to be at the event, and said he would go to watch as much as he could.
Silk was into "very social" mountain biking, and said if he came off, it took longer to heal up and ride again than it used to.
"Grade Two or Three tracks are my limit now. No more downhill."
But to watch the events was thrilling, his favourite to watch being downhill.
"Enjoying it - wishing I could be doing it. But it's just the adrenaline rush. I know how it feels, and just seeing the people of those ages doing those things is amazing.
"Good athletes too, strong athletes."
Silk said everything could be controlled apart from the weather, but so far it had not been so bad.
"It's going to be interesting how they do things with the weather."
