This is how a company in Basingstoke, Hampshire makes prosthetic legs.
They start at the bottom. The chemicals isocyanate and polyol are mixed together to make a rubber compound which is injected into a mold. One minute later a hard foot appears. Nine different sizes are available.
Next the shin is manufactured from carbon fiber, the kind of stuff you normally find on super cars.
After it's been laid out the sheet is baked under immense pressure for 90 minutes. This compresses the layers of carbon fiber into a thin light but immensely strong structure.
Next, come the joints. This is an ankle. Strength is crucial so it's machined from a solid block of aluminum. This is a five axis machining center, one of only two in the UK. The other belongs to a leading formula one team. It cuts out the ankle joint while fluid keeps the blades the cool. From raw aluminum to finished joint.
The component parts of the joint are then assembled. If the limb is designed for very active use then the design is incredibly complex.
This top of the range knee will take two days to build and contains hydraulics, brakes, micro-chips and even miniature motors. They all make the action and re-action of the joint as natural and stable as possible.
Finally the socket has to be manufactured - the bits that connects all this high tech wizardry to the patient. The hospital simply provides a digital map of the stump from which the foam caste can be produced. A hot plastic film is then draped over it and then vacuum packed against the contours.
A perfect fit every time. And for those who don't wear trousers; here's where they make the skin. It's a silicon compound available in 8 different shades and carefully tailored to mask the joins. Add in some padding and you'd never know the difference.