In some rehabilitation facilities and laboratories, lower-body exoskeletons and exosuits already are being used to improve walking ability in stroke patients, the elderly and young people with cerebral palsy or other disabilities. But perhaps the most tantalizing and vexing current science involves exoskeletons for the rest of us, including people who are young and healthy. In this area of research, scientists are developing exoskeletons to reduce the energy costs of running and walking, making those activities less fatiguing, more physiologically efficient and possibly more enjoyable.
So far, early results seem promising. In a series of studies conducted last year at Stanford University’s Biomechatronics Lab (and funded in part by Nike, Inc.), researchers found that college students could run about 15 percent more efficiently than normal on a treadmill when they wore a customizable, prototype version of a lower-leg exoskeleton. These exoskeletons feature a motor-powered lightweight frame strapped around the runners’ shins and ankles and a carbon-fiber bar inserted into the soles of their shoes. Together, these elements reduce the amount of force runners’ leg muscles need to produce to propel them forward. On real-world paths and trails, the devices might allow us to run at least 10 percent faster than on our own, the study’s authors estimate.
A slightly tweaked device likewise boosted the speed of young people while walking, according to a separate experiment from the Stanford lab, published in April. In that study, students walked about 40 percent faster, on average, when they wore a powered exoskeleton prototype, while incinerating about 2 percent less energy.
In essence, the exoskeleton technology could be considered “analogous to e-bikes,” but for striding, not pedaling, said Steven Collins, a professor of mechanical engineering at Stanford and senior author of the new studies. By reducing the effort needed to move, the powered machines theoretically could encourage us to move more, perhaps commute by foot, hang with or pass naturally speedier spouses or friends, and reach locales that might otherwise seem dauntingly hilly or far away.
They might even permit our muscles to power our cellphones, according to one of the more surprising of the new exoskeleton studies. In that experiment, published in May in Science, healthy, young volunteers at Queen’s University in Kingston, Ontario, wore an exoskeleton that included a backpack containing a small generator, which was attached to cables running down to their ankles.