A 13-year-old Auckland boy suffering from a crippling polio-like disease will walk again thanks to a world-leading US orthotist who has travelled across the globe to make it happen.

Harry Randall is the only New Zealander known to have acute flaccid myelitis (AFM), a polio-like disease he contracted from a virus when he was just 3.

For the past 10 years the North Shore boy has been using a wheelchair but he still manages to swim competitively, ski and perform a lead role in his school production.

With the use of his legs, he hopes to do much more.

American orthotist Marmaduke Loke travelled to New Zealand and on Friday spent five hours aligning Harry's feet and making several casts that he will take back to San Diego.

Harry pictured with by US orthotic specialist, Marmaduke Loke. Photo / Greg Bowker

There, Loke will design a carbon fibre brace specifically suited to Harry's correct alignment that will enable him to walk again.

In less than two months Harry - who calls himself the "one in a billion kid" - will travel to the US to get the brace fitted and take his first steps of freedom - just in time to start high school.

"It will be an amazing feeling to be able to walk again," Harry said, unable to wipe the smile off his face.

His mum, Vicki Randall, said it was "absolutely heartbreaking" finding out that her son may never be able to walk again.

"It started as a cough and flu-like virus when he was 3. He stayed in Starship for three weeks."

Doctors diagnosed Harry with Guillain-Barre syndrome, an autoimmune disorder, and the family were told he would recover in a year.

Unfortunately, that didn't happen.

"I started doing some research and we spoke to another US specialist, who was visiting New Zealand at the time, and said Harry had this polio-like syndrome, which there were very few cases of around the world."

Just last week, it was reported the Centers for Disease Control and Prevention (CDC) was investigating 28 new cases of AFM across the US, bringing the total number of suspected cases to 155.

Randall said it was not known how the virus was contracted, it was just "bad luck".

"Some people might get the virus and overcome it but for some reason Harry didn't and it affected his spinal cord."

She said they had been hoping groundbreaking technology would come along that would give Harry the ability to walk again and now it has.

"It's amazing, it will be so life-changing for Harry."

Harry has a polio-type condition. Photo / Greg Bowker

Loke - who has been developing sophisticated braces for the past 25 years - explained there are 26 bones in the foot and each one moves differently which was why getting the correct alignment was so important.

"We want to prevent damage to the knee and spine. If your car wheel alignment was out, a mechanic wouldn't just get new tyres, he would fix the alignment which is basically what we are doing," Loke said.

Due to the time it took to design and fabricate the brace, it cost between $12,000 and $40,000.

A Givealittle page has been set up to help fund Harry's braces.

At the moment it's not publicly funded but orthotics users and their families want to change that.

Gordon Jackman, 62, who contracted polio as a baby, is chief executive of the Duncan Foundation, a national support service for people with neuromuscular conditions.

The Duncan Foundation and Polio New Zealand have funded several trips to get Loke to New Zealand.

To date, Loke has helped 14 New Zealanders to walk again. Harry will be the second child.

WHAT IS AFM?

AFM is a rare, but serious condition that affects the nervous system. Specifically it attacks the area of the spinal cord called grey matter, which causes the body's muscles and reflexes to weaken.

Symptoms often develop after a viral infection, such as enterovirus or West Nile virus, but often no clear cause is found.

Patients start off having flu-like symptoms including sneezing and coughing. This slowly turns into muscle weakness, difficulty moving the eyes and then polio-like symptoms including facial drooping and difficulty swallowing.