From Wooden Legs and Leather Straps to Vacuum Suspension: In the not too distant past, before carbon fiber, CAD/CAM design, computerized knees, energy-storing feet, and other high-tech innovations, prosthetic components were wood, leather, or metal with straps and belts for suspension, designs that had changed little since the Civil War. However, since the late 1970s, methods, materials, and technology have moved componentry to state-of-the-art, with no end in sight.