"In France and Switzerland, from the late fifteenth through the nineteenth centuries, a variety of custom-designed limbs were built. Made of combinations of wood, metal, Leather|leather, and other materials, some of these designs were truly fantastic. Controlled by cables, gears, cranks, and springs, these limbs could be rotated and bent. There were prosthetic fingers made to grip objects. The limbs were not completely practical, as they had to be operated by a different hand, but they had their uses. For example, a hand could be cranked shut around a pen or fork. Flexing, spring-loaded legs were also available. These fantastic objects were ahead of their time: cable control was a precursor to the standard post-World War II design. Following those early designs, prosthetic limbs improved by leaps and bounds. World Wars I and II, as well as other large-scale conflicts, such as Vietnam, unfortunately increased demand for prosthetics, leading to improvements."