A powered ankle exoskeleton could make running easier

Engineers at Stanford University, funded by the National Science Foundation, are developing an ankle exoskeleton to enhance running efficiency and enjoyment. The device, tested on experienced runners, offers motor-powered and spring-based assistance, reducing energy expenditure by 25% when powered. Although not yet tested untethered, it could potentially increase speed by 10%. The exoskeleton reduces the workload on calf muscles, making running easier and more enjoyable. The team is optimistic about creating an effective untethered version, with a 15% improvement in energy costs over normal shoes, offering significant benefits for runners.

What potential improvement in speed does the team expect from untethered devices?

How does the exoskeleton assist runners in terms of energy cost?