Mechanical engineers at Vanderbilt University have developed a lightweight, low-profile ankle exoskeleton that they suggest could be worn under clothes without restricting motion, and does not require additional components such as batteries or actuators carried on the back or waist.

It could be widely used among elderly people, those with impaired lower-leg muscle strength, and workers whose jobs require substantial walking or running, they note, in a study published recently in IEEE Transactions on Neural Systems & Rehabilitation Engineering.

The study builds on a successful and widely cited ankle exoskeleton concept from other researchers in 2015, according to a media release from Vanderbilt University.

“We’ve shown how an unpowered ankle exoskeleton could be redesigned to fit under clothing and inside/under shoes so it more seamlessly integrates into daily life,” says Matt Yandell, a mechanical engineering PhD student and lead author of the study, in the release.

The team invented an unpowered friction clutch mechanism that fits under the foot or shoe and is no thicker than a typical shoe insole. The complete device, which includes a soft shank sleeve and assistive spring, weighs just over 1 pound.

“Our design is lightweight, low profile, quiet, uses no motor or batteries, it is low cost to manufacture, and naturally adapts to different walking speeds to assist the ankle muscles,” states Karl Zelik, assistant professor of mechanical engineering and senior author on the study.

“It could also help reduce fatigue in occupations that involve lots of walking, such as postal and warehouse workers, and soldiers in the field,” he adds.

[Source(s): Vanderbilt University, Science Daily]