Experience of phantom limbs lets amputees control real replacements

How they used to do it IN THE EARLY 16th century a knight called Gottfried von Berlichingen spent decades marauding and feuding on behalf of the Holy Roman Empire. He conducted most of his career singlehandedly--the other having been blown off by a cannonball. To replace it he had a metal duplicate made, with spring-loaded fingers that could hold a sword, shield or the reins of his horse. This early prosthetic device gave him the nickname "Götz of the Iron Hand". Prostheses have come a long way...