Prosthetic devices offer amputees independence and a chance of fuller life. But here in North America, when prosthetics are outgrown, most end up in the garbage. Handing down a used prosthetic would simply involve too many legal and health concerns for new users.

But a British charity is working on giving those discarded artificial limbs new life by collecting and refurbishing them and sending them to Africa, where prosthetic devices are scarce and costly.

The group is called Legs4Africa and was founded by professional photographer Tom Williams. His world changed four years ago while on assignment in Gambia when he met a man who needed a new leg.

Not really sure what he was doing, Williams took a few measurements and sent them to some British contacts in health care. They happened to find a discarded prosthesis that was the perfect size. Williams brought the leg back to the man as a surprise.

"That prosthetic leg not just changed his life, but the whole family. It lifted a huge burden off their shoulders," Williams told CTV News by internet video call.

By changing that one life, Williams started a movement.

"That particular story got into the press here in the U.K. and before I knew it, amputees from across the country starting sending me their old prosthetic legs," he said.

Williams and Legs4Africa soon collected some 500 discarded artificial limbs and mobility devices and sent them to a hospital in Gambia. There, staff took apart each of the prosthetics and re-built them to fit amputees.

Legs4Africa has since sent more than 3,000 prosthetic legs to Gambia, Tanzania and Zambia countries where car accidents, civil war and diseases such as diabetes are to blame for a growing population of amputees.

Williams admits he never intended to start a charity; he wanted to only help one man. But he realized a lot of people could be helped with what is essentially garbage to most amputees in the U.K.

"In a lot of Africa, having a prosthetic leg is almost often out of reach. It is almost considered an unrealistic thing to obtain," he said. "And I think that since we have been sending legs out there, there is a level of hope now."

Former Canadian soldier Michael Barnewall recently donated some old prosthetics to the charity.

Barnewall lost his lower leg to a landmine while on foot patrol Afghanistan in 2006. Today, he leads an active life as a member of the Canadian Amputee Hockey Committee.

Knowing how much his prosthetic has helped his mobility, he wanted to pass that on to someone else.

"If you've ever lost your independence, you understand just how important it is," he said.

"I just have these things sitting in my closet, so if I send them away I could quite possibly change somebody's life," he said.

One of the recipients whose life has been changed is Alieo Touray. The 52-year-old Gambian police officer was run down by a car several years ago and had to have his leg amputated. Three years ago, Legs4Africa helped arrange a prosthetic leg for him, allowing him to continue working as a police officer and support his family.

"I am still who I am and I could do whatever I was doing before," he says on a Legs4Africa video.

"I never think that a day like today would come back again, to have my life normal."

Legs4Africa have sent prosthetic legs to six countries and hopes to expand further, turning used parts into something priceless.

With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip