The former diesel mechanic, whose daughter's big day was pushed back twice to November, has seen his health improve dramatically in just under three years.

"I was a mechanic for 30-odd years," he said.

"I did my apprenticeship in Albury with Jimmy Azzi, then went to Weipa and got working on the big stuff in the mines.

"I came back, was working in Albury and then for the Army ... I was there for 17 years and then had an accident.

"That changed my whole life.

"I went to heaps of doctors, and had a back operation and (nerve) stimulators."

Mr Shanahan, who had 'R U OK?' tattooed on his hand after depressive episodes, said the pain eventually took over his whole body, prompting him and his wife to find a new doctor.

"I was falling over, giving myself a black eye and cracking a rib," he said.

"When I got into the wheelchair, I was in and out of hospital a lot and on ketamine.

"I changed doctors and she referred me to an exercise physiologist.

"I didn't like it for the first six months and they said, 'You don't get it yet Marty, but you will'."

With the guidance of Emma Pargeter and colleagues at Flex Out Physiotherapy, "Marty" went from the chair, to a wheelie walker and recently, to walking with poles.

"It was really challenging for him ... but he was open to trying everything," Mrs Pargeter said.

"Sometimes people get stuck in a bit of a cycle where because they're in pain, they can't move as much, and then because they can't move as much, they lose their strength.

"In the world of pain, there can be a reliance on medications or surgeries.

"The treatment that we've done with Marty is a bio-psychosocial approach and it's where the evidence is all pointing."

Mr Shanahan, who is sharing his story during National Pain Week, said what he learnt "blew him away".

"I read Pain Revolution books and went to Wangaratta to see one of their teams," he said.

"I thought pain was a purely physical thing ... I didn't understand the psychological part of the pain.

"Now, I understand.

"When I was in the wheelchair, I thought, 'This is it' ... but these guys have proved me wrong."

He now hopes to walk his daughter down the aisle, whose wedding was meant to take place on Easter Saturday, 2020.

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"Hopefully, it can happen," Mr Shanahan said.

"I'm looking to doing a speech, having a dance ... it was 20 years ago that I did that.

"I was hopeless ... now, I tell people now to persist in what they're doing, to read and learn."