After surgery, military personnel whose legs have been crushed or blasted can end up with a limb that looks healthy but is debilitated by pain and weakness. Some patients even ask for amputations. The Army solution is a sort of scaffold for intact but malfunctioning legs called the Intrepid Dynamic Exoskeletal Orthosis, and now, thanks to a company called Hangar, it’s going to be available to civilians too.

Basically, the IDEO is a carbon-fiber exoskeleton that attaches below the knee and connects to a foot plate that fits into a shoe. Taking a step and pushing off the plate loads the IDEO with energy just like a prosthetic running blade. Then it releases, providing auxiliary power to the leg. More than 500 people have gotten IDEOs since late 2009; about 60 of them even returned to combat. “Some of those blast injuries were pretty horrific,” says Ryan Blanck, who invented the IDEO as a prosthetist at Brooke Army Medical Center in San Antonio. But the loss of functionality from those wounds isn’t that different from problems caused by nerve disorders or car crashes.