For centuries, prosthetic limbs evolved so slowly that the ambulatory and functional gains they provided were offset by their limitations. An artificial device just couldn’t possibly replace a natural arm or leg.
But now, amputees are benefiting from innovative prosthetics — including hands that grasp and legs that support athletics. They look less artificial and behave more like near-natural extensions of the intricately mobile human body. The field of prosthetics is still far from perfect, but several advances are making artificial limbs “connect” more seamlessly to an amputee’s actions.
War Prompted First Innovation Cycle
Before recent advances in bionics and neurology accelerated the pace of prosthetic development, artificial limbs and support devices were constructed of wood, metal and various fibers. A wood and leather toe attached to a foot of an Egyptian mummy from as far back as 950 B.C. is considered by Smithsonian Magazine as the earliest example of a prosthetic device.
Over the centuries, the materials and shapes of prostheses changed — including a 16th century metal hand, pictured in Atlas Obscura, that looked like it was taken from a knight’s suit of armor — but expectations largely remained modest. These rudimentary substitutions offered little help with grasping objects and walking. They were also uncomfortable.
It’s widely accepted that the estimated 60,000 amputations performed on soldiers in the Civil War prompted science to improve prosthetics, according to the U.S. National Library of Medicine. Indeed, an artificial arm developed between the Civil War and World War I had a wrist that turned clockwise while the elbow bent, letting amputee veterans feed themselves. Artificial hands created after World War I featured movable fingers, said the BBC. Enhancements continued throughout the 20th century; plastics made for more flexible prostheses, and electronics were incorporated in an attempt to give amputees more control of them.
A Time of Rapid Advancements
Flash forward to this century, and prosthetics have reached a point where artificial hands and legs are more intuitive, comfortable and aesthetically pleasing. Amputees can more aptly grasp objects with prosthetic hands and rigorously compete in athletics with artificial legs. Microprocessors drive these improvements, making prosthetic limbs responsive and easy to control, while synthetics make limbs seem more like real flesh. And rapid prototyping has reduced the cost of prosthetic limbs.
“I’ve been amazed at how impactful rapid prototyping technology can be to the design process,” said Oscar Castillo, a Northrop Grumman engineering manager who leads the company’s FabLab in Redondo Beach, Calif. “Here at the FabLab, I’ve seen engineers leverage these technologies and their experience towards improving the lives of others with disabilities, from 3-D printed prosthetic hands to helping an artist with muscular dystrophy paint a little easier. It’s incredibly exciting and fulfilling work.”
Recent advancements are too numerous to completely cite here, but some innovative prosthetics include “power” knees that support climbing as well as bionic hands with motors in each finger to work off electronic signals, enabling responsive movement and gripping.
Science and Medicine Team Up
As The Engineer noted, prosthetic development focuses on two areas: refining current socket-based technology or creating new systems that directly integrate into the body. Integration tries to overcome the longstanding hurdle of artificial limbs being unable to communicate with the brain. U.K. company Cambridge Bio-Augmentation Systems is attempting the difficult step of integration by developing an interface that could be surgically implanted into the stump of an arm or a leg, where it would assimilate with bone and connect directly to nerves.
On that same track, MIT and Brigham and Women’s Hospital are hoping new treatments in medicine enable seamless integration of prosthetics and technology. Created by MIT and performed by Brigham and Women’s on a patient last year, a new surgery aims to pave the way for movement commands to be sent from the central nervous system to a robotic prosthesis.
A “Hero Arm” Builds Esteem
All these technological and scientific leaps also try to make amputees feel more confident with prosthetic limbs. Perhaps no product illustrates this more than Open Bionics’ Hero Arm, a 3D-printed prosthesis that, through its design, tries to make amputees feel like superheroes.
Luke Skywalker’s lifelike bionic arm isn’t here — yet. But prosthetic limbs are no longer uncomfortable, unseemly and unmanageable. They are helping amputees lead rich lives.