Co.Design

Bionic Legs, i-Limbs, and Other Super Human Prostheses You'll Envy

Save your tears for Tiny Tim. A boom in sophisticated prostheses has created a most unlikely by-product: envy.

There are many advantages to having your leg amputated.

Pedicure costs drop 50% overnight. A pair of socks lasts twice as long. But Hugh Herr, the director of the Biomechatronics Group at the MIT Media Lab, goes a step further. "It's actually unfair," Herr says about amputees' advantages over the able-bodied. "As tech advancements in prosthetics come along, amputees can exploit those improvements. They can get upgrades. A person with a natural body can't." Herr lost both his legs below the knee in a Mount Washington climbing accident when he was 17, but says that shouldn't inspire pity. Instead, by donning whirring, whispering, shiny supermachines — the robotic ankles that can propel him across the room in 400-watt bursts — Herr has been given: Power. Allure. The strange animal magnetism of the very bad boy.

"When the prosthetic technology doesn't work," Herr says, "and the [amputee] is limping and he can't run and he's hurting, then nobody feels threatened, because that person is labeled as 'cute' and 'courageous.' " He leans forward in his office and crosses his aluminum shins with an audible clink. "But when the technology works, when it can make you stronger or faster than you were, it overnight becomes sexy and powerful and threatening. Overnight."

Anybody who hears "prosthetic" and thinks "peg leg" might wonder about Herr's sunny hubris. The thought that an artificial limb could make anybody stronger or faster, or confer social advantage, is an opinion ripe for skepticism. Wearing one is inconvenient at best. It often hurts. It can break. It is obvious proof of loss. It seems by its very nature to announce a lack of health or vitality.

Yet much of the dissonance in Herr's "prosthetics as progress" thesis stems from the undeniable fact that for years, prostheses were irredeemably ugly, off-putting, scary. Who would call a disembodied limb a "design object" to be lusted after, like an Audi or an iPhone? Who would consider herself better, or more beautiful, than a person without one?

"When I first got this job," says Stuart Mead, CEO of Touch Bionics, a prosthetics and robotics firm based in Scotland, "it struck me how depressing it all was. Prosthetics were at the back of the hospital, the downstairs office, the back room. The look of most of these devices was horrible — half-human, half-plastic. This frightening pink color."

Just wearing one could induce shame: The Barbie doll cosmesis (a cosmetic cover), tipped with a hook, acted like social repellent, pushing the user and the observer apart. "It was like having a scarlet letter," says Marshall Young, an industrial designer for Otto Bock HealthCare, of the old-style prosthetic limbs. "It was, 'I've got this damn thing and now my life sucks.' "

All that is about to change — not only because prostheses are being built with materials found in sports cars and jet airplanes; or because designers are giving their creations an exuberant, unapologetic carbon-fiber sparkle; or even because nerve reintegration and myoelectrics are offering some amputees the joy of normal function. The biggest reason for amputees' unlikely rise into a new, socially advantaged class comes from something much more mundane: profit. The prosthetics business is set to explode, and its products will make amputees stronger, faster, and, to some, more desirable than the rest of us.

In the meantime, Herr says, you can dispense with the Tiny Tim pity and the warm fuzzy feeling you get when a little girl struggles to her feet on poorly designed stilts. Because the new machines — and they are machines — are becoming so lustrous and so efficient that some people are already willing to chop off a perfectly good limb to get one.

The $2.8 billion orthotics and prosthetics business revolves around a few major players: the German manufacturing company Otto Bock HealthCare; Iceland-based össur; Fillauer in Chattanooga, Tennessee; Ohio Willow Wood in Mount Sterling, Ohio; and patient-services provider Hanger Orthopedic in Bethesda, Maryland. There are also smaller manufacturers that supply components such as motors and microchips.

The industry receives regular media attention for its work with returning American soldiers, but those soldiers represent less than 0.1% of the 1.7 million amputees in the United States. Unfortunately, that customer base is about to get much larger. The Centers for Disease Control and Prevention has predicted that 29 million Americans will be diagnosed with diabetes by 2050 — increasing their chances of having a lower extremity amputated by a factor of 28. Hanger Orthopedic's CEO, Tom Kirk, points to diabetes and vascular disorders, largely driven by a 37% increase in obesity between 1998 and 2006, as the reason for most amputations. According to the CDC, diabetes-related amputations have risen to as many as 84,000 in a single 12-month period.

Not surprisingly, the money is following the market. MIT's Herr cofounded a company called iWalk, which has received $10 million in venture financing to develop the PowerFoot One — what the company calls the "world's first actively powered prosthetic ankle and foot." Meanwhile, the Department of Veterans Affairs recently gave Brown University's Center for Restorative and Regenerative Medicine a $7 million round of funding, on top of the $7.2 million it provided in 2004. And the Defense Advanced Research Projects Administration (DARPA) has funded Manchester, New Hampshire-based DEKA Research, which is developing the Luke, a powered prosthetic arm (named after Luke Skywalker, whose hand is hacked off by his father, Darth Vader).

This influx of R&D cash, combined with breakthroughs in materials science and processor speed, has had a striking visual and social result: an emblem of hurt and loss has become a paradigm of the sleek, modern, and powerful. Which is why Michael Bailey, a 24-year-old student in Duluth, Georgia, is looking forward to the day when he can amputate the last two fingers on his left hand.

"I don't think I would have said this if it had never happened," says Bailey, referring to the accident that tore off his pinkie, ring, and middle fingers. "But I told Touch Bionics I'd cut the rest of my hand off if I could make all five of my fingers robotic."

On March 5, 2008, Bailey was doing maintenance on a baling machine at a Conyers, Georgia-based paper-and-packaging company called Pratt Industries. The baler is designed to swing metal hooks across coils of galvanized steel ribbons and yank the strands tight around 2,100-pound bales of cardboard boxes.

"An inserter normally grabs the wires, breaks them, and then a hook twists them together," says Bailey. "The machine did its job — only it did it to my hand. It happened so quickly, all I could do was watch."

After nine hours of surgery, Bailey was left with two working fingers, his thumb and pointer. About a year and a half later, he was fitted with a prototype of Touch Bionics' new ProDigits, the world's first powered bionic-finger prosthesis.

He loves the thing. He shows it off. He likes to turn his head in unison with the flexing of his mechanical fingers, to make it seem like his entire body, not just his arm, is motorized. Like the Terminator.

"It's pretty surprising," Bailey says. "I find there are a lot of envious people. They say, 'Hey! I want a robot hand.' "

But Bailey is most surprised by his own reaction. "When I'm wearing it, I do feel different: I feel stronger. As weird as that sounds, having a piece of machinery incorporated into your body, as a part of you, well, it makes you feel above human. It's a very powerful thing."

Young, of Otto Bock HealthCare, says Bailey is far from alone. Amputees are now regularly removing healthy tissue to make room for more powerful technology. "I see it every day," he says. "People will get a second amputation — move their amputation up their leg — to get the prosthetic equivalent of a hotter car."

Orthopedic surgeons often consider amputation the equivalent of failure, Young says, and reflexively save as much of a damaged, injured, or diseased limb as possible. But in leaving lots of human being, they create a bigger problem: There is little room left for high-performance machinery. Now, the allure of that machinery has become so powerful that amputees are routinely taking the extreme step of paying out-of-pocket for what the industry calls "revisions."

"It's very simple," Young says. "Prosthetic feet act like leaf springs on a truck — the bigger they are, the longer the lever arms, the more energy storage and return you get. With enough clearance, you can go from a walking foot to a higher-performance running foot. So people with too much residual limb are in a position of saying, If I want to go to a knee that will let me play basketball, I will have to downgrade my foot. They'll say, Take four more inches, because I want that cool Corvette."

According to Young, whose firm supplies Walter Reed Army Medical Center in Washington, D.C., some returning soldiers undergo the same trade-up/trade-down decision, but with a twist: Double amputees are in the strangely fortunate position of being able to grow from 5-feet-8 to 6 feet tall — by choice.

Not surprisingly, all of this high-tech gear is expensive. One Otto Bock C-Leg, for example, connected to a custom socket (where the device is fit to the user's residual limb), plus a high-tech foot, can cost more than $50,000. Upper-extremity prostheses can be just as pricey. That leaves some amputees walking around with what Carrie Davis, who was born with one arm, calls a "bag of hands that's worth more than my house."

Davis is a 38-year-old mother of two and Hanger Orthopedic's national coordinator for Amputee Empowerment Partners, which provides mentors for new amputees. She's also a two-time national champion in the "female upper-limb amputee division" of the Olympic distance triathlon.

And because her arm is made of black carbon fiber and titanium and makes cool whirring sounds when she picks up a wineglass, conversations tend to follow her.

"Well, I'm instantly intriguing," she says. "There's this black arm sticking out of my shirt sleeve. And when I'm wearing what I call my 'pretty hand' [with a natural-colored cosmesis], and somebody asks if I hurt my elbow, I say, 'No, but check this out! Ever see one of these?' "

Hugh Herr got his master's in mechanical engineering at MIT and his PhD in biophysics at Harvard, but if his bold pronouncements about the advantages of prostheses still sound merely futuristic (and self-serving), consider: In 2008, a South African sprinter named Oscar Pistorius wanted to compete for a spot on his country's Olympic team. Pistorius's personal best for the 400 meters was within a few tenths of a second of the Olympic qualifying time, and he wanted a shot at the Games. But track and field's international governing body, the IAAF, instead banned Pistorius from competition, citing the undeniable fact that Pistorius has no legs. Or, rather, he has residual limbs and runs on carbon-fiber Cheetah legs made by össur. The IAAF alleged that Cheetahs gave Pistorius an advantage over elite athletes who run on two natural limbs.

The turnabout — to say nothing of the irony — was dramatic. Where once we pitied the amputee and cheered him as he struggled to his feet for the first time, now we wanted him banned for being too ... strong.

Another way to look at it: Someday soon, the Paralympics, which are essentially the second-tier Olympics — held after the "real" Games, in front of sparse crowds — will be the place for sports fans to go to watch people really going faster, higher, and stronger.

Herr was an expert witness in the case that caused the Court of Arbitration for Sport to overturn the IAAF ruling; his testimony included statistics that showed Pistorius's prostheses to be mixed blessings at best. Among those: His foot is in contact with the ground 14% longer on each sprinting step than an able-bodied sprinter's (a disadvantage), but he spends 34% less time in the air between steps and takes 21% less time to swing his legs between steps, and has a "metabolic cost of running" that is 17% lower (all factors in his favor). The upshot: Pistorius is approximately equal to his able-bodied competition for the moment — but could be only a couple of upgrades away from being able to leave the Usain Bolts and Tyson Gays of the world in the dust.

The problem for Herr, though, was that the IAAF was not going to ban the gear Pistorius was using; they were going to ban Pistorius himself. They weren't barring a piece of technology, as FINA (swimming's governing body) did with Speedo's original LZR Racer swimsuit; they were going to toss an entire person. One top IAAF official claimed the reason was simple: Pistorius was "affecting the purity of the sport." That's the same language used for decades to keep blacks out of pro basketball and girls out of Little League.

"I've seen it," says Matt Albuquerque, founder of Manchester, New Hampshire's Next Step Orthotics and Prosthetics. "Able-bodied people do fear this advantage on the part of the amputee. They fear that you aren't just 'normal' again, you're better than human. And nobody wants the one-legged guy beating you. You're not bragging about that at the dinner table, I guarantee you."

Albuquerque says many patients come in to his practice with a "peg-leg mentality" — the assumption that they'll be forever held back by substandard, unbeautiful technology — only to discover that some people are actually afraid of competitors connected to sleek, powerful devices. "One of my buddies was on the wrong side of a cable when an F-16 landed on a carrier in Vietnam," Albuquerque says. "Amputated both his legs, right there on the deck. Turns out, he's a great golfer. And I'm a fairly small guy, about 5-foot-4. We like to play together. But nobody wants to play us at the golf club, because nobody wants to get beat by the midget and the guy with no legs."

As the rhetoric heats up — as robots perform surgery and build automobiles, and as the suspicion grows that our original equipment is somehow deficient — Herr offers some perspective. Poor eyesight, he says, is a medical condition. Eyeglasses are prosthetic. And while they were once purely medical devices, they're now expensive fashion items.

"Let me make a point," Herr says. "Eyeglasses — it's a fucking sex apparatus. Often people can have contact lenses, but they choose in certain social environments to wear their glasses, because it looks hot. People put glasses on to make themselves look more intelligent. To augment their appearance, not just their performance."

Herr's suggestion, of course, is that the better prostheses make us perform, and the more glamorous they look, the more beautiful they will make amputees seem, too, even though their sheen, contour, texture, and color have ceased to look human.

"What is the obsession with looking human?" he says. "You think the only beauty is human? Bridges can be beautiful. Cars can be beautiful. Cell phones can be beautiful. They don't look biological. So why do you anticipate 30 years from now that amputees will give a shit about human beauty? They won't. Their limbs will be sculptures."

Paul Hochman is the gear and tech editor for Today on NBC and host of msn.com's GearDaddy.

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3 Comments

  • Ferial

    Beautiful!!
    "You think the only beauty is human? Bridges can be beautiful. Cars can be beautiful. Cell phones can be beautiful. They don't look biological. So why do you anticipate 30 years from now that amputees will give a shit about human beauty? They won't. Their limbs will be sculptures." 
     Loved this part!! 

    As an undergraduate biomedical engineer, I find this very thrilling.

  • Shawn

    I want this tech sooo bad; I can't wait for the day that upgrading can be affordable to the average person!

  • Supernerdboy

     Wow nobody has left a comment? Nice read, with the subtraction of the over use of the clench of using cars as a simile. I will embrace this tech and anybody who want to augment. I used to were glasses but am planing to get a new pair next year and you make it seem like a good thing.