Sportswear is getting a robotic upgrade. A new exosuit, which is worn like a pair of bike shorts, makes both walking and running more energy efficient.
Philippe Malcolm at the University of Nebraska Omaha in the US and his colleagues developed the flexible suit, which cuts the energy a wearer uses when walking by 9 per cent and the energy spent on running by 4 per cent.
This exosuit isn’t the first to cut the energy spent moving – others have been able to make either walking or running alone more energy efficient – but Malcolm and his team say it is the first to aid in both. The device could eventually be used by people who spend a long time on their feet, such as rescue workers, firefighters and military personnel.
The exosuit weighs 5 kilograms and consists of two fabric wraps around the thighs that are connected to a fabric waist-belt. Cables that run from the belt pull on the thigh wraps to assist with hip extension.
The suit uses a sensor on the torso to detect whether the wearer is walking or running, while sensors on the thighs detect changes in leg position. A motor unit on the back of the suit begins pulling a cable just before a wearer’s front foot hits the ground, aiding the body’s natural hip extensors and reducing the amount of energy spent to generate the same force.
The cable goes slack when the back leg is moving forward while walking or running. “When that happens there’s almost no movement restriction,” says Malcolm. He and his team tested the suit on nine participants on treadmills, who each walked 450 metres over 5 minutes and ran 750 metres over 5 minutes, both with the suit switched on and off.
The energy savings are modest, and the next stage of research will require longer time trials to determine whether the exosuit can help a wearer run faster or for longer.