This mechanical exoskeleton makes walking more efficient - We just don’t know yet

This hints at something that researchers will undoubtedly have to investigate: what are the effects of wearing the exoskeleton for long periods of time, on a regular basis? Given what happens when people spend a lot of time in wheelchairs, it’s possible that a user's leg muscles would become weak with extended use. "My instinct is to say that if you wore it all the time, the body would recognize the parallel pathway, and the morphology of your leg would change," Sawicki says. But "we just don’t know yet."

It took over five years to come up with this design. And the fact that they were able to do this at all has a lot to do with advancements in medical imaging techniques. "That whole 'clutch-holding and Achilles-stretching' thing — we didn’t know about that until the late 2000s, when people were started using ultrasound imaging to look at what muscles were doing," Sawicki says. Thanks these techniques, researchers were able to see that the calf muscle and the Achilles tendon were acting like the clutch and spring in the exoskeleton. "It changed the way we look at exoskeletons."

There’s a lot that the exoskeleton can’t do right now; it really only works at certain speeds. "The device in the paper will break during running," Sawicki says. The researchers still have to find a way to make a sturdier (and bulkier device) that can withstand harder impacts. Different materials, like electroactive polymers, might help them do that. "We need to build a device that can do it all." Still, if all you want to do is go for a walk, the exoskeleton can help. People who like to go hiking might want to wear it, Sawicki says. The exoskeleton might also prove useful for military personnel. But what the team is really interested in are the medical applications. "It could be a mobility aid for people who have had a stroke," Sawicki says. Given the regulations surrounding medical devices, the exoskeleton might end up making it to market as a recreational device first, however. Sawicki thinks that the final product would cost a little under $1,000.

"Even if we could build Ironman, how practical would it be for regular use?"