By Amber X. Chen

Biomechanists have just created a revolutionary bionic knee that helps amputees with a remarkable range of movement. Traditionally, lower leg prostheses are an external device. An amputee’s stump is fixed with a socket upon which a robotic limb is attached. But now, researchers at MIT have developed a prosthesis that is directly connected to a patient’s bone and muscle tissue, and it feels more like a part of their own body.

Since 2017, a team of scientists at MIT’s Yang Center for Bionics—co-led by biomechanist Hugh Herr—have been working to develop better, more advanced prostheses that are integrated into an amputee’s body. In a new study published last month in Science, the researchers have brought together different technologies to create a tissue-integrated, above-the-knee prosthesis that gives people more control over their movements.

“We actually are pushing the definition of what a prosthesis can be, and that’s why we say it’s a tissue-integrated prosthesis,” Tony Shu, lead author of the study, says. “There’s a part that you will never be able to take off without another surgery.”