A newly invented wearable device could provide support, succor and an unexpected boost in speed to runners who might otherwise not be able to keep up with their training partners or former selves, as well as people who might like to try running but fear it is just too hard. The device, a kind of lightweight harness worn around the midsection and legs, can increase someone’s running efficiency by about 8 percent or more, according to a new study, making running feel much easier and also raising interesting questions about whether and how we should augment natural human abilities. In recent years, biomechanics labs around the world have been experimenting with various devices meant to ease the difficulties of moving for both people and their silicon counterparts, robots. Because walking is such a fundamental form of movement for independence and health, most of this past research has been directed toward that activity. The research has generally focused on various types of what the scientists call exoskeletons, although the devices often are localized to specific joints. Some use batteries or other energy sources to provide extra power, which can compensate for weakness in someone’s body. Others are unpowered and simply reinforce or amplify whatever force people wearing them can generate. Recently, Rezvan Nasiri, a graduate student at the Cognitive Systems Laboratory at the University of Tehran in Iran, began to wonder about running. A competitor in judo, Mr. Nasiri was jogging one evening to try to maintain his weight for an upcoming meet when he began to pay close attention to his stride. “I realized that after each ground impact, my legs lost energy,” he says. This recognition was not really a surprise. Experts in biomechanics long have known that running can be a somewhat wasteful motion. We create energy when we coil our muscles and push off with one leg from the ground and dissipate some of it when our foot returns to the pavement and momentum slightly brakes. Jogging along, Mr. Nasiri began to consider whether it might be possible to harness some of that squandered energy. If so, he reasoned, the key would be to work with the hips. Much of the action in running involves our hips, which are far more important during this activity than during walking. Mr. Nasiri finished his run, returned to the lab the next day and, with the help of several colleagues, began to tinker. What he and his collaborators hoped to do was, in essence, couple a runner’s hips in ways that nature has not, so that the energy created by one leg as it completes a leg swing and moves backward might be sent over to the other leg as it starts forward, reducing the activity required of that hip’s muscles and decreasing the overall energy costs of running. The researchers tried out ideas and eventually developed a lightweight contraption involving a belt around the hips connected to metal straps butting against the thighs that are held in place by straps above the knees. The device also includes a metal loop arching out from a person’s back that acts as a spring, gathering and transferring energy from one hip to the other. He and his collaborators, who included the head of the lab, Majid Nili Ahmadabadi, tried the device on a robot, on themselves and, finally, on 10 local male runners. They asked the men to run on treadmills for 10 minutes at a steady pace of around nine minutes per mile while wearing the device and without it, as the scientists monitored their energy expenditure. And they found that the men were much more efficient with the device, reducing the energy cost of their running by about 8 percent. That should mean that someone wearing the device would be able to run longer, faster or more easily. By comparison, the much-touted Nike high-performance running shoe, the Vaporfly 4%, is said to improve running efficiency by the stated 4 percent. Already, word of the invention has excited interest and speculation among other experts. “There’s a beauty to this device,” says Rodger Kram, an emeritus professor of biomechanics at the University of Colorado in Boulder, who reviewed the study for IEEE Transactions on Neural Systems and Rehabilitation Engineering, which is publishing the study today. “It’s a simple, elegant concept that cleverly allows people to use their own muscular power more effectively,” he says. But its invention also inevitably brings up issues of technological doping. Some people might hope to use the device to achieve race times otherwise impossible for them, Mr. Nasiri admits. But the device is conspicuous, he continues. It sticks out at the back. Observers can tell if runners don one, he says, mitigating opportunities to deploy it for a secret advantage. He would prefer that people use the device openly to jog together, even when their paces differ, he says, and he hopes it might entice people who otherwise avoid running to try the sport. There is no timetable for when the device may become commercially available, though he expects to begin conversations with manufacturers soon, he says. At the moment, he and his colleagues continue to fiddle with the design, hoping to reduce its weight, price and any discomfort runners of varying sizes might experience while wearing it. He says that the volunteers in the study reported that the device felt unobtrusive during their test runs. He also would like to study the device on a wider variety of runners, he says, including swift professionals, women and plodding or first-time participants. Meanwhile, he is struggling to come up with a catchy name for the thing. “We would welcome suggestions,” he says. The New York Times
