A wearable exoskeleton can help runners increase their speed by encouraging them to take more steps, allowing them to cover short distances more quickly.
While previous studies have focused on how wearable exoskeletons can help people reduce the energy they expend while running, the new study, published today in Science Robotics, examines how wearable robots can assist runners as they sprint.
The exosuit could prove a useful tool for athletes looking to speed up during training. “Although this is a preliminary study, we can say the exosuit can augment the human ability to run,” says Giuk Lee, an associate professor at Chung-Ang University in Seoul, South Korea, who led the research.
Lee and his team built a lightweight exosuit with steel cables powered by electrical motors attached to the runner’s thighs. The motors pull the cables, mimicking the contraction of muscles. The exosuit helps people run faster by assisting their hip extension—the powerful motion that propels a runner forward.
The exosuit tracks the wearer’s lower-body movements in real time through sensors on both thighs. This data feeds into an algorithm designed to monitor gait, which works in tandem with other algorithms to track each runner’s individual running style and speed.
The team tested the exosuit on nine young male runners, none of whom were considered to be elite athletes. They were given three-minute training sessions on how the exosuit works before they ran for short bursts on a treadmill to familiarize themselves with how it feels to wear.
They then sprinted outside in a straight line for 200 meters twice, once wearing the exosuit and once without. They rested for a minimum of 30 minutes between trials.
On average, the participants managed to run the distance 0.97 seconds faster when they were wearing the suit than when they weren’t.
The researchers observed that the less time it took runners to complete the distance, the more steps they took, suggesting that the exosuit helps shorten the sprint time by increasing the frequency of the runner’s steps.
Buoyed by their findings, the researchers have set themselves ambitious goals. They’re working on a customized exosuit for Kyung-soo Oh, a former national elite runner in South Korea who had retired, in a bid to beat the world record for running 100 meters. The current men’s record is 9.58 seconds, set by Jamaican sprinter Usain Bolt in 2009.
The researchers are also starting to work with a disabled runner to examine whether an assistive exosuit could offer a benefit.
“It’s a great achievement, what they have done,” says Kaspar Althoefer, head of the Center for Advanced Robotics at Queen Mary University of London, who was not involved in the study. He is curious about how the exosuit could help sprinters cover even shorter distances.
“If they could manage to make a world-record holder run 0.68 seconds faster over 100 meters, I think it would be massive,” he adds.
However, training wearing such exosuits is unlikely to help athletes to run more quickly in races where they’re not allowed to don assistive technology. Although the suit encourages wearers to move their legs faster, it doesn’t help their muscles grow stronger, Althoefer says, pointing out that over-reliance on exosuits could, in theory, make runners weaker over time.