Walking Assist Clutch (IMAGE) U.S. National Science Foundation Caption An unpowered clutch engages a spring in parallel with the Achilles tendon when the foot is on the ground, offloading the calf muscles and making walking easier. Credit Steve Collins Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.