Casts haven't changed much, over time. Maybe it's because the job they have to do is so simple: Keep the limb stable, steady, and stiff. But they also have to meet other, collateral demands: For example, in disaster zones, where supplies are hard to come by. And why do we still have plaster casts, which throw such an enormous wrench in the life of the wearer?
Here's three designs that aim to meet those challenges--and one old classic, as a bonus:
The ingenious Prio Paper Cast , designed by Nicholas Riddle, is currently in contention for the Dyson Awards. It took 150 prototypes to create the final version, which can be easily shipped and stored, and assembled in a mere two minutes, without any medical expertise. The idea is that it could aid triage efforts in disaster zones, or anywhere medical expertise is scant:
Yoon Bahk's Emergency Cast  is a similar idea, with a tad less of the Prio's gee-whiz factor. The basic support comes flat-packed; the arm is them isolated with an inflatable bladder:
The other two were concepts, but this one's a real product . The Exos arm brace  is waterproof and transparent to X-rays---meaning that it never has to be taken off in the shower, or to get a check-up X-ray. Removing it is as simple as adjusting the dial that controls the Boa lacing :
Finally, you can't write about braces without mentioning what's probably the most beautiful leg-splint ever , designed by Charles and Ray Eames. Developed at the request of the U.S. Navy during WWII, it was modular and easy to mass produce--and, incidentally, a beautiful piece of industrial sculpture. This was really where the Eames legend began: Thanks to access to military equipment, the Eames were able to perfect their techniques in molding plywood. They went on to apply these in the iconic furniture designs we now known them for: