Retired volunteers in Aberdeenshire collect and dismantle the limbs so they can then be given a new life.Read more
BBC Scotland reporter
Hero, three, from Herefordshire, is trialling the prosthetic which has a number of attachments.
Andy Webster severed his arm while baling hay, but his friends are determined to help him.
Jayne Hardman, from Redditch, says her prosthetic noses help her "face the world".
It's high-tech, it's cheap, and it's been designed for amputees in the developing world.
Scientists are developing made-to-measure devices to improve daily life for amputees. John shows how long it takes to get moving normally.