ONE part engineer, one part artist. Toss in a vast knowledge of anatomy and physiology, a good grasp of mechanics and electronics, problem-solving skills and, of course, a sympathetic ear.

That's a rough recipe for one of the health profession's most specialised jobs — the prosthetist.

Melbourne-based practitioner Kevin Harrison started out as a carpenter working in hospitals when he realised he no longer wanted to build walls and cabinets, but rebuild people's lives after illness and accident.

After stints as an assistant to nurses and physiotherapists, he met a prosthetist and saw the light — "I thought, 'That's what I'm going to do.' I knew it, I just knew it," he says.

"It's such a great field to be in, it suits me very well. I really like making things, I really like working with people. I love problem solving.

"There's a lot of art in what I do, a lot of science … there's not one time you could just pull a limb off the shelf and say: 'That's for you.' It's all customised."

After undertaking Australia's only prosthetics degree at La Trobe University as a mature-age student, Mr Harrison began his new career 10 years ago and now specialises in above-the-knee amputees.

His patients include Sydney Morning Herald reporter Cynthia Banham, who appeared in public recently walking on her new limbs, after losing her legs in the Garuda plane crash in Indonesia last year, and Gerry Jenkins, the Australia-Pacific boss of Chrysler, who lost his right leg in a motorbike accident in 2004.

Mr Harrison also works with many Australian Paralympians, and next month will take on one of his greatest challenges in a team of 126 volunteer prosthetists and wheelchair technicians from around the world at the Paralympic Games in Beijing.

The experts, including 10 from Australia, will work up to 20 hours a day from the athletes' village and competition venues, fixing and adjusting prosthetic limbs and wheelchairs, often just minutes before an athlete competes.

The free service is provided by Paralympics sponsor Otto Bock, a prosthetics and orthotics supply company, which ships in containers of parts and constructs a workshop on-site in which sockets (that join the false limb to the amputee's stump) can be custom-made and new prostheses built and fitted.

"Some of the guys from Third World countries, that's (the only time) when they get their leg repaired," he says.

"We take for granted what we can give to an Australian amputee. When you can give something so simple to someone and it changes their life, that's when you do get that really big feeling of achievement."

But Mr Harrison is more modest about his contribution at home, saying he doesn't see his role as particularly special.

"The people I'm working with, they put in so much more effort than I do. I'm just blown away by what they achieve."

Prosthetic limbs can cost from $150 for the most basic foot, up to $120,000 or more for an above-elbow arm that uses the most recent technology.