SMART NEWS

Getting the Prosthetic Is Easy, Compared to Getting It To Do What You Want

Contributor

November 27, 2012

A growing number of soldiers are returning from duty with injuries that have stolen away their limbs. Thankfully, prosthetic technology is getting better, and many of these amputees are learning to live with new arms and legs. But while getting the prosthetic might be costly, it’s learning how to use it that’s the real struggle.

The New York Times tells the story of Cpl. Sebastian Gallegos, who lost his arm in an I.E.D. explosion in Afghanistan. His robotic arm cost something like $110,000. It’s a nice one —the kind with sensors that can read signals from his brain and motors to turn those signals into movement. But that makes it sound easy. The Times writes:

Close hand, raise elbow, he says to himself. The mechanical arm rises, but the claw-like hand opens, dropping the sponge. Try again, the therapist instructs. Same result. Again. Tiny gears whir, and his brow wrinkles with the mental effort. The elbow rises, and this time the hand remains closed. He breathes.

Success.

“As a baby, you can hold onto a finger,” the corporal said. “I have to relearn.”

Gallegos is one of over 1,570 American soldiers who have lost a limb to injuries in Iraq and Afghanistan. Of those, less than 280 have lost arms. And in many ways, those arm prosthetics are far more difficult to use than prosthetic legs. It’s all in the hands, writes the Times:

Among orthopedists, there is a saying: legs may be stronger, but arms and hands are smarter. With myriad bones, joints and ranges of motion, the upper limbs are among the body’s most complex tools. Replicating their actions with robotic arms can be excruciatingly difficult, requiring amputees to understand the distinct muscle contractions involved in movements they once did without thinking.

In fact, over half of upper arm amptuees chose not to use their prostheses at all, simply because they are too hard to use. Th enew kind Gallegos is still difficult to use, but his work at trying to master it might just help those in the future, as prosthetics designers try to improve their tactics.

And of course, soldiers aren’t the only ones in the world using prostheses. The National Center for Health Statistics estimates that there are nearly 50,000 new amputations every year, and something like 25,000 people lose an arm each year.

For them, the $100,000 prosthetic might be out of reach. But hopefully, some day, designers and users like Gallegos will come to a cheaper, easier solution.