Turns out being a living giant is bad for your health. And making matters worse for NBA players: smashing those massive bodies into each other repeatedly. Oh, and changing directions at full speed. And leaping as high as one can before landing on hardwood floors. Far too often, these physical requirements of basketball have cost great players the careers they'd once seemed destined for, and have cost fans the chance to watch those players meet their potential. But if you don't believe it, just ask Yao Ming. Or Andrew Bynum. Or just about anyone drafted by the Trail Blazers. Find those guys and more on our list of the greatest NBA careers derailed by injury, in no particular order.