Almost everyone who\u2019s used underarm crutches agrees: they are terrible. They\u2019re hard on your wrists, they cause falls, they cause nerve damage. This is why almost every country in the world has abandoned them. Except the U.S., where if you go to the hospital with a leg injury, you\u2019re most likely going to leave with adjustable aluminum crutches. In this third installment of our series exploring how gear gets made, we look at the fascinating history of why better designs for crutches haven\u2019t caught on, and whether or not they ever will.