An unexpected result of losing his legs to frostbite in a climbing accident when he was seventeen, says professor Hugh Herr, was that he’d eventually be able to add and subtract to his height at will. On this summer’s day at the Massachusetts Institute of Technology’s futuristic Biomechatronics lab, where Herr leads a team as head of research, he was three inches taller than nature intended.
Office walls were covered in maths equations, shelves were filled with foot castings, and the room’s centrepiece was an elevated walkway on which research is conducted on amputees. Herr’s trouser bottoms were rolled up, leaving no mystery to what lies beneath them: the gleaming bio-mechatronic masterpieces his lab invented, which restore the ability to walk to those who have lost it. It is called the BiOM and hailed as the most advanced prosthesis ever created, ushering in a new age for amputees.
Prostheses have remained relatively primitive while other fields have advanced radically. The earliest recorded artificial appendage, made from wood and leather, dates to ancient Egypt; and prosthetic users could finally contract artificial appendages with their muscles in the 1800s. But amputees today remain resigned to inconvenient realities: appendages can cause discomfort, periodic replacements are sometimes required and, most importantly, they don’t operate in total harmony with the human body. The BiOM, however, takes orders directly from the nervous system, via sensors and synthetic skins, which control a muscle-like motor, moving the user around in unprecedented organic harmony. In 2005 Herr, 50, also developed the Rheo Knee, a computer-operated artificial knee that provides walking control by stiffening and relaxing a magnetic fluid in the user’s joint.
Wounded army veterans were among early BiOM users but the new technology and MIT expertise is now accessible to civilians with appropriate health coverage.
The invention won wide acclaim outside the scientific community last year during a poignant TED talk, when Adrianne Haslet-Davis, a dancer who lost her left leg in the Boston Marathon bombings, appeared on stage using one of the appendages for a lively rumba with a male partner. After this, Herr declared to the audience: “A human being can never be broken.”
But Herr’s path to becoming the face of one of science’s new eras was wrought from personal experience. It began in his youth, when he was not involved with science, but was a rising star of the American rock climbing scene, and endured a horrific accident.
Born to a Mennonite family in rural Pennsylvania, nature was his habitat; and his interest in conquering the giant rock formations of the North-east came at an early age. He was a prodigy by 11, scaling walls previously unclimbed by 15. And he climbed without rope. “If you fall, you’re dead,” he said of such heights.
The climb that altered his life came in 1982, when he and Jeff Batzer, another accomplished climber, went to scale New Hampshire’s notoriously challenging Mount Washington. They scaled 600 feet of ice in over an hour without issue. Another climbing feat seemed in reach, but winds suddenly picked up to 100 miles per hour. Temperatures dropped. Their jokes and conversation diminished. Snow turned to blizzard. Visibility went to zero. “You know you hear stories of a person parking their snowmobile, walking five paces, and then they can’t get back and they die?” Herr said.
They thought they saw salvation in tracks from just such a snowmobile, leading them to believe they were approaching civilisation and the end of their torment. But the path took them farther into the remote reaches of the mountain. When they both fell into a river the cold engulfed Herr from the waist down.
They spent three days searching for ways out, passing nights in the small caves they created by digging holes beneath boulders, where they would hold each other to maximise warmth. On the third day they prepared for death, telling each other happy memories of home. With hardly enough strength left to speak or move, a woman appeared through the trees.
She was part of a search party that had been hunting for them. Herr and Batzer were airlifted that night to a hospital in New Hampshire and it was there Herr would discover the consequences of his plunge into the river. His feet had “stopped looking like human feet,” he said. “They looked like they were going to burst, they were so swollen.”
He also discovered that a member of the rescue team, a 28-year-old volunteer named Albert Dow, had died in an avalanche during the attempt. In Herr’s mind, Dow’s death came at the cost of preventing his own, and the morbid contrast had a profound effect on him. He has never spoken to the family – “I don’t have the right,” he has said – and the feelings fuelled him with a sense of purpose that has defined his scientific pursuits.
Doctors amputated Herr’s legs just below his knees that March, outfitting him with plaster prosthetics. The adjustment was emotionally disturbing, and yet he thought only of returning to climbing. And so that’s what he started doing, on his ill-suited early appendages, soon after release. “Emotionally, climbing was my way out,” he said.
To the climbing community’s surprise he returned to the sport with fervour, designing better prosthetics of his own out of fibreglass and wood, until he was eventually climbing mountains of the same difficulty level as before his accident. The media came calling, bringing him fame. His nickname was ‘Mechanical Boy’.“I went from feeling embarrassed by my new body to celebrating artificial limbs and my new body type.”
In 1985, aged 21, and curious to learn how he could push boundaries further, Herr enrolled at a local college to study physics. “It was this extraordinary intellectual birth,” he said. He got his PhD in biophysics at Harvard and his post-doctorate at MIT, following which he joined the team at Harvard, and then became part of the faculty at MIT. The ambitions of his Biomechatronics lab have since come to represent the pinnacle of modern prosthetics technology.
Herr has stepped gracefully into the societal role of visionary in recent years. He can no longer tease students the way he used to, by asking them at a semester’s end if his gait was normal or pathological, to which they would usually reply normal – at which point he would dramatically raise his trouser leg. He’s too visible to get away with it these days.
He transcended academia and invention, perhaps touching on activism, when he defended South African sprinter and double amputee Oscar Pistorius in 2008, after Pistorius was banned from competing in the Olympics. Herr’s tests proved Pistorius had no mechanical advantage over other runners, reversing the IAAF’s ban.
Seated in a lab room at MIT with his legs crossed, he tried foreseeing the future for the amputee community.
“We view our cells and tissues as somehow holy and spiritual,” he said. “That somehow synthetics are less spiritual. But that will change. You can embed humanity into any material. It doesn’t really matter what we’re made of.”
He concluded: “I wouldn’t want biological legs now if you offered them to me.”