This is a great use of 3D printing. BMW has used this technology to create Thumb Braces for their employees. They help prevent repetitive stress injuries, and have been working very well. It's amazing to see all the uses of 3D printing, that most of us would have never imagined. Take for example a car manufacturer using the technology not only in helping build cars, but to make sure their employees are safe as well.

Read more about this at http://3dprint.com/7911/bmw-uses-3d-printing/