Well, by ish 236, Machine Man has put himself back together in order to save his friend/psychologist from a very angry Hulk, but he's in too big of a hurry to repair himself altogether. Thus, he's carrying one of his arms while he runs to intercept the Hulk. Courtesy of Sal "Brings It" Buscema, scripted by Roger Stern, providing the first truly "badass" moment of Aaron Stack's career where he actually defeats the Hulk. By himself. A robot.
Stack reminds the Hulk that the ugly part of the bruise is purple.
http://www.spacebooger.com/ reminds you that whatever you call it, whether a severed arm or a "figment of your imagination," it still hurts.