Springing Forward With New Technology

Cindy Charlton has little trouble opening lids on jars or scrubbing pots and pans. Not too surprising - until you realize this Denver mother of two sons uses an artificial arm. "Being able to grate and peel carrots and cucumbers may not be a big plus to some people, but to me it is. It's all simple stuff, but it means a lot - especially when you have two active sons!"

Four years ago, Charlton nearly lost her life to necrotizing fasciitis, a deadly infection commonly known as the "flesh-eating bacteria." She survived, but doctors had to amputate both her legs below the knee and her right arm below the elbow.

Charlton's ability to do ordinary household tasks would be severely limited without her myoelectric arm - just one of many recent advances in prosthetics that are making life easier for people with amputations.

Her PM&R physician, Robert "Skip" Meier, III, MD, explains, "A myoelectric arm picks up impulses from the nerve that are amplified into a motor that make the elbow bend or straighten out, or the fingers open and close." Charlton wears polish on the nails of her myoelectric hand, and sports her grandmother's wedding rings on one finger. "We still don't have individual finger control," says Dr. Meier, a specialist in amputations and rehabilitation who is director of Amputee Services of America, "But with the development of robotics, we'll get more fine finger movement over time."

Charlton, who thinks of herself as "the bionic woman," recalls, "Dr. Meier asked me what my rehab goals were and I said, 'Well, I basically want to walk.' He looked at me and said, 'If that's all you want to do I can have you on your feet in two weeks.' " She realized that she had options when talking with her physician and prosthetist. "You have to be very clear about what you want to do with your life. Do you want to run marathons? Do you want to live a soccer mom life like I do? Your activity level is going to determine what kind of prostheses you're going to get."

Charlton loves the new "springlike" feet she has. "I'm considered a 'heavy user,' because I walk on two prostheses, and I'm so active, chasing my two kids," she says. "These feet take heavy impact, but they're still very lightweight. They're springy - when I walk, they have a little bounce - and they don't wear out as fast as others I've had."

As recently as the 1980s, explains PM&R physician Alberto Esquenazi, MD, state-of-the-art technology for prosthetic feet was just a piece of wood that had rubber in the shape of a foot, without toes. Scientists began using lab-created materials in the development of artificial feet in the mid-1980s. But the real explosion in prosthetic foot technology - and the inspiration for Cindy Charlton's "springy" feet - came from Vietnam veterans like Bill Denby who lost both his legs in the war, innovative research programs at the Veterans Administration, and federally funded programs for creative minds like Van Philips, a young prosthetist and amputee who came up with the idea of using the same technology for artificial feet that's used in downhill skiing.

"The foot is a big spring, and in order to make a big spring you need to use big springy materials," explains Dr. Esquenazi, director of the Regional Amputee Center and the Gait and Motion Laboratory at Moss Rehabilitation Institute and assistant professor at Jefferson University School of Medicine, both in Philadelphia. "Imagine a downhill ski. It doesn't lay flat on the ground. Apply pressure onto it, and you'll see it flex. As you let go the flexion stretches back. That gives you energy storage and energy release."

PM&R physicians can even fit their patients with "hybrid" prosthetic feet that work well for both high-impact activities like running as well as more moderate activities. "I used to have to fit my patients for a running foot and leg and a walking foot and leg; now you can have one that serves both purposes," Dr. Esquenazi explains.

These advances in technology, along with others such as microchips that control artificial knee joints, don't come cheap. "Some myoelectric arms can cost about $110,000," says Dr. Meier. "We need to combine the best of rehabilitation available in the U.S. with prosthetics to get the most benefit from this technology."

To do that, Dr. Meier advocates a team approach, something already central to how PM&R physicians practice their specialty. "A variety of experienced amputation and rehabilitation professionals sit down with the patient to come up with a rehabilitation plan to empower them to be free of health care systems and regain control of their lives. That's the essence of rehabilitation - to restore control when something's been taken away from you."