The Special Challenges
of Artificial Arms
By Heather Martino
Why veterans who lost their legs do better — and how the VA is trying to do more to help those who lost upper limbs
Mike Kacer unlaces his worn-out combat boots. Practicing with his mechanical left arm, he maneuvers two silver pincers, oversized tweezers that tug his laces loose. It does not go well.
Lacing up his shoes is even harder. “I could actually tie the shoe faster without the prosthesis,” the Army veteran says.
Despite practicing with this artificial arm — and with more than a dozen other Army-issued prosthetic limbs at his disposal — Kacer said that most of the time he doesn’t wear the devices. That’s true even though the government has probably spent more than $117,000 to provide him with artificial arms over the past five years. One of the more sophisticated devices he owns cost more than $100,000, and it’s a device he doesn’t often use.
“If I had to put a timeframe on it,” he says, in “a 13-hour day I probably wear a prosthetic four to five hours out of it.”
Kacer’s ordeal began while he was serving in Afghanistan. In June 2008 a rocket exploded within a few feet of him, fracturing his skull, breaking his jaw and ribs, and mangling his left arm, which had to be amputated.
He has had plenty of company from the wars in Iraq and Afghanistan. Of the roughly 1,600 veterans who have suffered major limb losses in those conflicts, about 319 have faced amputations of at least part of an arm. And although these survivors have little trouble getting artificial arms, many abandon them. The former soldiers criticize the devices as uncomfortable, unreliable and painful to wear regularly, according to a 2012 study by the inspector general’s office at the Department of Veterans Affairs. “Consistently, veterans with upper limb amputations only reported lower psychosocial adjustment, physical abilities, and prosthetic satisfaction than those with lower limb amputations,” the inspector general’s investigators wrote.
In other words, soldiers who lost legs adjusted better than those who lost arms. Scientists have greatly improved prosthetic legs during the past decade with better technology, materials like carbon fiber, and rehabilitation. But artificial arms have not kept pace, according to some specialists. “The state of the art of upper limb technology is not as good as lower limb technology,” said Dr. Linda Resnik, a Brown University scientist who works at the VA Medical Center in Providence, R.I.
A key reason is that artificial arms have not gotten the same priority, according to experts and the VA inspector general. Veterans under treatment found that VA staff were unfamiliar with arm prosthetics, according to the inspector general, and that the VA lacked expertise and had not kept up with the latest technologies. Repairs took longer for artificial arms than for legs, and arm amputees felt that the VA did not really listen to their expressed needs.
Since 2007, the VA has had detailed guidelines for working with soldiers getting prosthetic legs. Similar guidelines for those who lost arms were ordered up — at the inspector general’s urging — five years later, in 2012. Those new guidelines for artificial arms actually were issued only this year — seven years after the guidelines for artificial legs.
One big problem is that arms are much more complex than legs. Since the 1950s, researchers have vastly improved the materials in prosthetics, but not their mechanics, according to research by Gary Berke, a Stanford University instructor who operates a private clinic providing prosthetics. This has especially benefitted those who use artificial legs. Materials like silicone and polyurethane have helped decrease the mechanical forces applied to the remaining stump. Additionally, carbon fiber and other lighter and more durable materials have allowed leg amputees to exert less energy when walking, making the task easier than ever before.
In any case, “walking is relatively straightforward,” Berke said, adding that leg prosthetics enable “linear activities” with much simpler demands. Artificial legs essentially can do everything that real ones do. Artificial arms, however, are not nearly as adept as the real things. Patients expect their artificial arms to do more, and researchers have much more work to do. “We’re behind the eight ball in terms of [artificial arms’] functional ability,” said Berke.
Confounding the slow progress is rising expectations from soldiers wounded in today’s wars. In the Vietnam era of the 1960s and 1970s, soldiers died on the battlefield from injuries that would be treatable today, and survivors who made it home were not given many choices for prosthetics, said Lynne McFarland, an epidemiologist with the VA in Washington state. “When they were injured there wasn’t a lot of research on upper limb prosthetics,” she said. “It was basically the kind of hook and grasper thing that was available to them.”
Rather than the old-fashioned, pirate-style hooks, today’s amputees get the choice of robot-like arms. These new devices may look like the real thing — but they still can’t act like real arms. Many veterans are not impressed. “Even with all the high-tech stuff, even then they kind of went, ‘You know, it’s not worth the bother,’ ” said McFarland, referring to the reality that many veterans abandon their arm prosthetics.
While he lost almost all of both legs, and comparatively little of his left arm, Masson is emphatic: ‘I’d rather lose a leg than lose an arm.’
The problem is growing. Among the 44,800 living veterans of all U.S. wars with major limb amputations, about one in 10 are missing at least some part of an arm. Among veterans of Iraq and Afghanistan, however, about one in five are arm amputees, according to November 2013 statistics.
Arm amputees now account for 22 percent of all new amputees according to Resnik. But in the last fiscal year, the VA’s Prosthetic and Sensory Aids Service spent $70.2 million for artificial legs, while just $5.9 million was allocated for prosthetic arms.
If anyone understands the fundamental differences between arm and leg amputations, it’s Army veteran John E. Masson.
Masson’s family has a history of military service dating back to World War II. John, who grew up in Indiana, served his first tour of duty during Operation Desert Storm in 1990 and ’91. Two of his three kids were born while he was in the service, with tours taking him to Iraq and South America.
Later, he was part of the surge of U.S. troops in Afghanistan. On Oct. 16, 2010, the Special Forces medic stepped on an explosive device in southern Kandahar province. His left hand, the one he favored for writing and throwing, was blown off below the elbow. Both of his legs were decimated. Those injuries extended all the way to his hip.
His legs were almost entirely amputated. There is little tissue between Masson’s sacrum (what he calls his “butt bone”) and what is left of his hip. When the 42-year-old veteran sits up, his lower body is wedged into a carbon fiber bucket. He finds it very uncomfortable. He perseveres, struggling to adapt to his new life and, with his wife, raising his three children.
Yet while he lost almost all of both legs, and comparatively little of his left arm, Masson is emphatic: “I’d rather lose a leg than lose an arm.”
Masson’s reasoning echoes that of many veterans.
Like Masson, two out of five amputee veterans have lost more than one limb. More than half of them still experience pain when they use their artificial arms, according to the VA report. Sometimes the pain is moderate, other times severe.
The pain happens in large part because of difficulties getting prosthetics to fit onto what remains of survivors’ arms.
Doctors and technicians have to adjust artificial arms for the scars that are left after amputation. Prosthetics can be fitted with suctioning devices that ensure a firmer fit, but suction can be hard to keep if the person sweats and what remains of the real arm gets slippery.
In addition, bodies keep changing. Some veterans gain or lose substantial weight. That changes the size of what remains of their arms. Even if the patient maintains the same body weight, these stubs can grow or change shape. An artificial arm that was once tailor made now fits badly. Skin gets irritated. Blisters form. Bruises appear. Those in the medical field call this issue “socket fit.”
“Achieving a proper socket fit is very difficult,” said epidemiologist McFarland. Her research found that almost a quarter of Iraq and Afghanistan veterans abandoned their artificial arms. A leading reason, based on interviews with those surveyed, was discomfort from poor fitting limbs.
Masson put it this way: “It gets irritating.” His discomfort is not imaginary. Tucked inside his artificial arm is a liner, a thin material that rests between the stub of his arm and his prosthesis. Just pushing himself around in his wheelchair causes friction with the stub. The result is that he cuts through liners, which must be replaced two or three times a week.
In addition to discomfort, Masson has found that a bad socket fit can cause embarrassment. The longer he wears his prosthetic arm, the more he sweats, so the more likely it is to slip off. He recalled his most embarrassing moment when, in public, he was wearing his prosthetic legs and fell. When he went to push himself up, his prosthetic arm slipped off, causing him to fall again.
“Now you gotta deal with, ‘I’m on the ground.’ It’s disgusting, strangers are around watching,” Masson said.
“At that point in time, you start to feel useless and you realize how much you rely on other people as amputees,” Masson said. “As service members, we don’t like to think that we need to depend on other people at all.”
There are other difficulties, like the burden of carrying around a prosthetic. Even lightweight artificial arms can cause a strain. Kacer, the veteran who lost his left arm in a rocket attack, said that when he has worn prosthetics, he faces a problem outsiders might never imagine: The longer he wears them, the heavier they tend to feel. And then they become painful. “Your body has this natural imbalance that it compensates for,” Kacer said, “so, I just get tons of knots in my back.”
Like many veterans who are missing arms, Kacer finds that he has had to be issued a number of prosthetics to restore some of the functionality he lost. There’s the arm that helps him ride a bicycle, for example, and the arm, with a net attachment, that helps him play catch with his nephews. (He wasn’t wearing it at Yankee Stadium in 2011 when he managed to make a great catch of a foul ball by reaching with his baseball cap.)
Despite the variety of devices, veterans still find it hard to grasp even simple objects with artificial arms.
“We have expectations of being able to hold people’s hands and pick up a penny off of a table,” said Stanford’s Berke, “and be able to cook and hold things in different positions and comb our hair and get them wet.” But prosthetics fall short, he said. “They don’t have the capability to do the things a normal hand does.”
It’s not because robotic motors don’t have the ability to grasp something. They can do that. It’s because these devices are unable to feel what they are doing. Scientists call this a feedback loop: Those who have their natural arms use their muscles and nerves to work together. In artificial arms, said Berke, “There’s no feedback from the hand to the limb, so people can’t say, ‘Yes I have a grip on my cup of coffee and I’m not going to smash it.’ ”
Dr. Robert Yang, who conducted the interviews for the VA inspector general’s report, said the lack of feedback is yet another reason why veterans often abandon using a prosthetic. “When we use our arms we rely on the sensation we’re getting that allows us to fine tune our movements,” Yang said, “and that’s extremely difficult to substitute.”
Despite all the difficulties, some researchers believe that if the military put a greater emphasis on making prosthetic arms more functional, the results could be a lot different. Today, veterans who have lost only their hands and forearms tend to wear their smaller, lighter prosthetics longer and more comfortably. Even heavier devices for full-arm amputees would become more popular, some researchers argue, if they could be made more functional.
Brendan Marrocco decided not to wait for the military to get arms right.
It was Easter Sunday 2009 when the then-22-year-old Army specialist was returning to his base in northern Iraq. He had been out on night patrol, and was driving an armored vehicle. That’s when Marrocco hit a roadside bomb. Both his legs and both his arms were blown off, making him the first quadruple amputee to survive the Iraq War.
At first, he got prosthetic legs. He found those easy. “You don’t have to learn anything besides balance,” he said, and putting one foot in front of the other.
Artificial arms were harder. Marrocco had to learn how to operate each prosthetic. That meant differentiating between opening and rotating in one direction with one muscle group, and closing and rotating the prosthetic in the opposite direction with another muscle group.
“You have to learn the difference between the two,” he said. “Otherwise you’re going to make a mess.”
Marrocco grew frustrated with his local VA in Brooklyn. He felt the facility could not cope with his needs. He relocated to the Walter Reed National Military Medical Center, which is run by the Department of Defense (not by the VA). He believes the joint military hospital does a better job. “Pretty much whenever you want a new leg or need an adjustment they’re right there, they’ll do it on the spot, and if you want a new leg they’ll order it within a week or two,” he said.
‘We have guys still using hooks — still using things that have been around
for 100 years’
Remaining at Walter Reed meant that Marrocco was better able to see the progress of his fellow amputees as they learned to use prosthetics. He observed that veterans who lost both legs, even those with amputations above the knee, were “walking close to normal.” He said, “It’s really incredible considering what they’ve been through.”
But arm amputees were different. “When you look at arm prosthetics we have guys still using hooks — still using things that have been around for 100 years,” Marrocco said. “Even the more advanced hands themselves that I have used really weren’t that convenient.”
Marrocco grew more frustrated with his prosthetic arm. “It’s really heavy and cumbersome,” he said. “You don’t have much dexterity with it.”
His solution was unprecedented for a U.S. veteran: a double arm transplant. After three and a half years on a waiting list and winning medical approval for the procedure, Marrocco underwent a grueling 13-hour surgery at Johns Hopkins Hospital in Baltimore in December 2012, getting two arms from a cadaver transplanted onto his stubs. He was the first person to have the surgery at John Hopkins, and one of only seven people in the United States to have undergone successful double hand transplants.
“This is a lot more natural and easier,” said Marrocco. “Every single aspect of my life so far has seen improvement.” One of the biggest improvements for him is feeling independent again — able to dress himself, handle a service dog and drive a car.
“I spent four years without arms and now that I’m back to having them,” Marrocco said, “it was like I never didn’t have them.”
Single-amputee Kacer is betting on artificial arms with improved technology. He’s been working with a private company, Advanced Arm Dynamics. During a recent visit to the company’s facility in Philadelphia, Kacer tried the company’s i-Limb Ultra Revolution, an artificial arm that can be controlled through an app. He can use his real hand to control whether to twist, turn or grip with the artificial limb.
That, too, takes some adjustment. He found using his real hand to manipulate an app almost counterproductive. “If you still got a good hand,” he said, “you’re going to use your hand.”
Other ideas are in the pipeline. The Defense Advanced Research Projects Agency (DARPA) launched the Revolutionizing Prosthetics program in 2006. Two years later, DARPA and the VA entered into an agreement to begin collaborating on research. This resulted in veterans with major limb amputations entering pilot programs.
So far the program has funded the development of two arms. The APL arm, named for the Applied Physics Laboratory at John Hopkins University, where the arm is being developed, is controlled by wires that go into the wearer’s brain and sense neuron activity.
The DEKA arm, also know as the Luke Arm — for Luke Skywalker — can translate signals from nearby muscles to control its movements.
Unlike current prosthetic devices, the DEKA and APL arms have sensors that provide feedback on grips, to avoid holding a cup of coffee so tightly, for example, that it shatters.
In May, the U.S. Food and Drug Administration approved the commercial development of the DEKA arm, although tests by 39 service members from 2008 to 2012 were inconclusive, according to Brown University’s Resnik.
“We only had subjects training with the use of the prosthesis in the laboratory setting and they were supervised at all times,” Resnik said. “And so we couldn’t really tell how well subjects would accept the arm, or what the impact was really on their daily life function at home.”
Additional studies are underway among several groups of veterans in New York, Tampa and San Antonio. The veterans are subjecting the DEKA arm to everyday use. Resnik declined to disclose any results yet, and said the study would continue at least until 2015.
In the meantime, veterans like triple amputee John Masson are left to work with the artificial arms available. “Of course it’s challenging and it’s going to be challenging,” he said. But he is optimistic about improvements to artificial arms, and also about his ability to adapt to his injuries.
“An injury like this, you can’t let it rule you and stop you from doing things,” Masson said. “Sky’s the limit.”
