A project from a couple of Masters students in mechanical engineering at Brigham Young University, FlexLegs is sort of like a cross between crutches and Oscar Pistorius's super-fast lower-leg prostheses. They promise to allow those with lower leg injuries to walk, run, tackle steps, and more. Say the creators: "If we can help a person with no legs to run, why can’t we help a person with an injured leg to walk?"
It has advantages over regular crutches, even space-age crutches like the MobiLegs we tested awhile back. The FlexLegs system doesn't require the use of your arms or hands, for one thing, and also lets you walk with your regular rhythm, rather than the swinging way you walk with crutches. That said, it also seems like it might be uncomfortable with extended use, and we're not sure about cramping or losing feeling in the lower leg--plus, you can't use it if you're wearing a cast. But as the video shows, it is definitely more natural for getting around than crutches--could be a good option for those prone to ankle sprains. The team is working on getting the FlexLegs into production now.