This story is part of The Salt Lake Tribune’s ongoing commitment to identify solutions to Utah’s biggest challenges through the work of the Innovation Lab.
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New technology from the University of Utah is helping leg amputees get their movement back through the use of an exoskeleton machine.
The exoskeleton, an experimental machine from The U.’s Bionic Engineering Lab, is designed for people who had a leg amputated above the knee. Amputation above the knee significantly hinders movement of that leg because the knee joint is lost and much of the muscle that helps propel the leg’s motion.
To make up for that lack of strength, these amputees will often overexert their intact leg or overwork their hip.
With the exoskeleton, which wraps around the wearer’s waist and is strapped to the thigh, amputees get an extra boost while walking. Because it’s made of carbon fiber, plastics and aluminum, the exoskeleton is lightweight -- only about 5 ½ pounds.
(Trent Nelson | The Salt Lake Tribune) Tommaso Lenzi and Marshall Ishmael with on an exoskeleton to assist leg amputees at the University of Utah on Wednesday, Oct. 13, 2021.
In a study published in the journal Nature, above-the-knee amputees used less energy while walking -- an equivalent of letting go of a 26-pound backpack -- when they used the exoskeleton. They still used a bit more energy compared to able-bodied people, but researcher Tommaso Lenzi called it a “really big improvement.”
“It makes a big difference in how far you can walk, and also how enjoyable it is for you to walk and go about your day,” Lenzi said.
About 1 million Americans have had leg amputations, Lenzi said, meaning this technology could positively affect many lives.
The exoskeleton isn’t going to turn wearers into superheros. It’s more like an electric bike adding a bit of oomph to your speed than an ultra-powered mechanical suit. It helps move the hip joint in two ways, propelling the leg forward while stepping and pushing back on the leg while the other foot steps forward.
The machine is designed to work with many brands and types of prostheses, Lenzi said. Each of the 12 subjects in the Nature study used their own while testing the exoskeleton.
“We’re trying to find a solution that, while being functional, will also be practical and available within a relatively short amount of time,” Lenzi said.
Lenzi, who has been working on robotics for more than 10 years, started this project about four years ago as he’s been working with rehabilitation hospitals.
(Trent Nelson | The Salt Lake Tribune) Tommaso Lenzi, center, walks with an exoskeleton that provides assistance for leg amuptees while walking, at the University of Utah on Wednesday, Oct. 13, 2021. At left, monitoring the device, are grad students Marshall Ishmael and Brendon Ortolano.
“Looking at the struggle that all these people are living with,” Lenzi said, “it really made me realize that technologies are a possible solution for these issues and help them improve their quality of life.”
While currently being tested on amputees, Lenzi said he hopes the machine will be able to help others, including people who have had a stroke or are elderly.
“The idea is, if you’re able to walk, but it’s just really hard for you for whatever reason, this device can make it easier for you,” Lenzi said.
Research on the exoskeleton is funded by nearly $1 million from the federal Department of Defense, which hopes to use the machine to benefit wounded veterans, and more than $575,000 from the National Science Foundation.
With that funding, Lenzi said the exoskeleton can be made available on the market in a couple years.
