Hugh Herr began designing prosthetic limbs because the ones available to him after a devastating climbing accident in 1982 were nowhere near good enough. At 17, Herr lost both legs below the knee to frostbite after being stranded on Mount Washington in New Hampshire. The standard prosthetics he received let him walk again, but they were clumsy, limited, and completely useless for the thing he cared about most: rock climbing. So he started building his own.
The Accident on Mount Washington
In January 1982, Herr and a climbing partner had just completed an ice route near the summit of Mount Washington, a peak notorious for extreme and unpredictable weather. A storm trapped them on the mountain, forcing them to shelter in a cave for days. Elite volunteers from the Mountain Rescue Service launched a search, but with no way to pinpoint the climbers’ location, teams split up across the mountain. During the search, an avalanche killed Albert Dow, a volunteer rescuer and well-known climber.
Herr and his partner were eventually found alive, but both suffered severe frostbite. Herr lost both legs below the knee. The tragedy of Dow’s death and the life-altering injuries from the ordeal became a turning point that shaped the rest of Herr’s life.
Standard Prosthetics Weren’t Good Enough
The prosthetic legs Herr received were designed for basic mobility. They let him stand and walk, but their rough design couldn’t come close to replicating what a healthy leg could do, let alone handle the demands of technical rock climbing. Herr was determined to get back on the rock, and the gap between what he needed and what existed pushed him into a machine shop.
He started fabricating his own legs, optimized specifically for vertical terrain. He built specialized attachments that let him adjust his height anywhere from five to nine feet tall, giving him reach that no biological climber could match. He designed narrow foot pieces that could balance on razor-thin rock fissures and grip vertical ice walls. With these custom limbs, Herr climbed at a more advanced level than he ever had before his accident. Rather than viewing his body as broken, he began to see the technology as the thing that was broken and in need of fixing.
From Machine Shop to MIT
Herr’s early tinkering was driven by intuition and necessity, but he quickly realized that truly transforming prosthetic technology required a deep understanding of physics, engineering, and biology. He enrolled at Millersville University, where he earned a bachelor’s degree in physics. From there, he went to MIT for a master’s in mechanical engineering, then to Harvard for a PhD in biophysics.
During a postdoctoral fellowship at MIT focused on biomedical devices, Herr began working on advanced leg prostheses and orthoses, devices engineered to replicate the actual function of a human leg rather than just its shape. In 2000, he took over a research lab at MIT that eventually became the Biomechatronics Group within the Media Lab, a team dedicated to merging biology with mechanical and electronic engineering to build limbs that move and respond like natural ones.
A Philosophy of Ending Disability
Herr’s motivation went far beyond personal convenience. He developed a clear philosophical stance: disability is not a property of the human body but a failure of available technology. “My doctors were wrong because they took a common view of my body,” Herr has said. “They viewed me as broken. They viewed technology as static. But technology is not a static thing; there is innovation.” He flipped the framing entirely. He wasn’t the problem. The prosthetics were.
That perspective became the engine behind decades of work. Herr has described the central challenge of bionics as eliminating disability through biology, technology, and design, calling it “the challenge of the century.” His inventions consistently reinforced his belief that inadequate technology was the only real obstacle standing between amputees and full physical capability.
Building Limbs That Feel Like Part of the Body
Herr’s most ambitious work has focused on making prosthetic limbs that don’t just move on command but actually feel like part of the wearer’s body. His approach, called NeuroEmbodied Design, aims to blur the boundary between biological and synthetic systems entirely.
One major breakthrough involves a surgical technique that preserves the natural pairing of muscles in a residual limb. In a healthy leg, when one muscle contracts, its opposing partner stretches, and that stretch sends signals back to the brain about position, speed, and force. Traditional amputations sever these muscle pairs, cutting off that feedback loop. Herr’s team developed a modified amputation procedure that surgically reconnects opposing muscles in the residual limb, restoring that natural back-and-forth communication. Small electrical signals from a bionic prosthesis can then stimulate these muscle pairs, giving the wearer a sense of where their prosthetic foot is and how much force it’s applying, without looking at it.
This work addresses one of the deepest limitations of conventional prosthetics. Even the most mechanically advanced artificial leg feels like a tool strapped to the body if the brain can’t sense it. By restoring the neural conversation between limb and brain, Herr’s designs move closer to limbs that feel owned rather than worn.
Why It Started With Climbing
The through line of Herr’s career traces back to a teenager who refused to accept that losing his legs meant losing his identity as a climber. That refusal sent him to a machine shop, then to a physics classroom, then to the most advanced biomechanics labs in the world. Each step was driven by the same conviction: if the body works but the technology doesn’t, you fix the technology. What began as a personal project to get back on a rock face became a decades-long effort to redefine what prosthetic limbs can be for everyone who needs them.