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Arm Amputees Rely on Old Devices

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Arm amputees rely on old devices

By Dave Moniz, USA TODAY

QUANTICO, Va. — Sgt. James "Eddie" Wright can drive a car, shoot a rifle and handle a bayonet.

That seems unremarkable unless you know this: Wright has no hands.

They were blown off in a fierce battle near Fallujah, Iraq, in April 2004, when his unit was ambushed by about 40 insurgents. This summer, after intense rehabilitation, Wright returned to active duty in the Marine Corps as a martial arts instructor.

It is perhaps telling that he uses traditional metal hook prosthetics as his new hands. The only double-arm amputee from the Iraq war to return to military service, Wright chose the World War II-era technology instead of several newer, battery-powered prosthetic hands now on the market.

"I remember when I first came back for rehabilitation, they were touting the myoelectric (battery-powered) hands as the greatest innovation. I was so disappointed," Wright said, describing how the hooks are much easier because they don't fall off his arm, are supple enough to "pick up a paper clip" and are much more reliable than battery-powered limbs.

Recognizing that the technology for hands and arms hasn't improved significantly in the past six decades, the Defense Department is embarking on a multimillion-dollar research program to revolutionize upper-body prosthetics. Over the next four years, the Pentagon will fund development of what it hopes will be vastly improved artificial hands and arms that can be controlled by the central nervous system. (Related story: Military to fund prosthetics research)

Richard Weir, a Department of Veterans Affairs scientist in Chicago, says the Pentagon probably won't be able to achieve every goal right away. But Weir said he believes the research will spin off better technologies for long-suffering arm amputees.

"I imagine we'll see a big advance in the next couple of years," said Fred Downs, a Vietnam War amputee who is the VA's chief consultant for prosthetics.

A variety of artificial arms are available for military personnel and civilians. They range from flesh-colored artificial hands that are solely cosmetic to cable-controlled hooks, such as Wright's, to battery-powered arms with motors that control elbows and hands.

Only about half of all arm amputees who are fitted with prosthetics even use them, said Joe Miller, who oversees prosthetics at Walter Reed Army Medical Center in Washington, D.C. Many are heavy, hard to use and prone to break.

The vast majority of Americans who use prosthetic devices are leg amputees, according to the Amputee Coalition of America, a non-profit advocacy group in Knoxville, Tenn. Of the 199,000 Americans using artificial limbs in the mid-1990s, the latest figure available, about 87% were missing feet or legs.

"There is no commercial market for upper-extremity devices, and this is something we have argued to the Pentagon," said Lt. Col. Paul Pasquina, medical director of the amputee program at Walter Reed.

Pasquina said the limitations are widely known and a source of frustration to doctors and patients alike.

Artificial arms are much more difficult to design than artificial legs and have proved a harder sell to skeptical patients. Leg amputees typically need a prosthetic device to move around and are therefore more likely to use one. A single-arm amputee can often get along without a prosthetic. Adding motors and other materials needed for an easy-to-use artificial arm has been a huge challenge, said Weir, a researcher and artificial-hand designer at Northwestern University.

A typical adult human arm, Weir said, weighs about 5.5% of a person's total body weight. So someone who weighs 170 pounds has arms that weigh more than 9 pounds each. But even a 6-pound artificial arm, he said, is too heavy for most to wear very long because it doesn't have the support that a natural arm has.

Weir said there is a challenge in duplicating the functions of a hand, which can move in dozens of ways.

"The artificial hand is a very poor gripper if you can only keep it in one shape," he said, noting that no artificial hands on the market can simulate the hand muscle movements necessary for daily living.

Perhaps the most difficult hurdle for those who use artificial arms and hands is a lack of natural control. Devices known as "body-powered" arms, which have hooks that are manipulated by cables and harnesses, are controlled by gross movements of the shoulder, arm and chest.

Another type of artificial arm, known as myoelectric, is battery powered and is controlled by the movement of remaining arm and chest muscles. These devices amplify electrical signals from muscle twitches to power the artificial arm.

Many arm amputees, including Wright, choose to use the traditional metal hook or nothing at all.

Miller, the Walter Reed prosthetics manager, said he believes that within four years, the new research will yield hands and arms that are lighter, easier to control and more flexible. "We hope to have a prosthetic that looks and functions normally," he said.

Full article, including pic, found here on the USATODAY.com site.

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I've come across established arm amps using 'traditional' devices a number of times. I met someone once who swore by using his ''hook' as he said it was so versatile - amongst other things, he could open beer bottles with it - very impressive! :)

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Some arm amps are amazing. . .I ran across one that was able to pick up a cigarette ash with his hooks without breaking it  :blink:

That IS amazing! WOW B)

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I agree. I use a cable operated claw that is extreamly durable and gets the job done. Myo electrics are great for social life, but when you want to get dirty non electric is the way to go. You don't have to worry about getting it wet, hot and cold. Am I going to break this $10,000 unit by breathing on it too hard. The hooks and gryphers have harnesses that hold the arm on 70% more. So he is right.


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