In 1994 - 95 I worked with a guy who had a left below elbow prothesis. It was worse than a mannequin's arm. The fingers were all the same length, and fixed in partial flexion. Wasn't really much use, and looked ridiculous. I am fascinated and excited about the development of prosthetic arms/hands/partial hand prosthetics over the past decade or so. They have come on massively in a relatively short time span, and they're only going to get better.