Body Tune-Up

By Meredith Camel

Body Tune-Up

By Meredith Camel
Songs and sounds that can help amputees walk better, safer, stronger? Frost School of Music researchers are blending music, engineering, and medical disciplines to make sure there’s an app for that.

Could Rocky Balboa have beaten Clubber Lang if his training montage hadn’t been set to Survivor’s “Eye of the Tiger”? Maybe, but once Rocky III audiences heard those up-tempo rock riffs, they wouldn’t dream of exercising without adding the track to their Sony Walkman cassette tapes.

Colby Leider, associate professor and director of the Music Engineering Technology program at the Frost School of Music, knows a lot about musical motivation. Vibhor Agrawal, Ph.D. ’10, assistant professor in the Department of Physical Therapy at the Miller School of Medicine, is a biomedical engineer who specializes in prosthetics and amputee biomechanics. Together they are orchestrating a first-of-its-kind collaboration among musicians, biomedical engineers, and physical therapists to create a mobile app that motivates amputees to knock out harmful walking habits.

The unlikely marriage of these disciplines began in 2010, when Robert S. Gailey Jr., B.S.Ed. ’82, M.S.Ed. ’86, professor in the Department of Physical Therapy at the Miller School of Medicine, arranged for his then-teenage son, Max, to chat with Leider about the Frost School’s Music Engineering Technology program. While in Leider’s office, Gailey took note of a graduate student’s research poster—a system that measures runners’ steps per minute and selects songs from their iPod library that have the same number of beats per minute. Gailey, who holds a research appointment at the Miami Veterans Affairs Medical Center and is an advisor on prosthetics to the U.S. Department of Defense, immediately thought of the potential for soldiers who’ve lost limbs in Iraq and Afghanistan.

“I know a whole lot of amputees who are already listening to music,” Gailey said. “So if we can get their music to talk to their prosthetics and vice versa, the sky’s the limit in terms of rehabilitation.”

For 20 years Gailey has fitted patients with prosthetics made by an Icelandic company called Össur, which has bestowed a research grant to Leider and Gailey to design and conduct a clinical trial of a new mobile app that employs audio, visual, social media, and haptic (vibration) feedback. The various signals let users know if they’re walking in a way that could cause body fatigue, ulcers on the stump attached to the prosthetic, or stress on the non-amputated leg, which greatly increases risk of double amputation.

“It’s a computer, it’s a phone, it’s a musical instrument—and by the way, you can talk to your knee on it,” Leider says, pointing to his iPhone.

The Össur study is one of six research projects presently under way at the University’s Functional Outcomes Research and Evaluation (FORE) Center on the Coral Gables campus, including a study funded by the Anesthesia Patient Safety Foundation on how the cacophony of hospital alarms and monitoring devices affects stress levels in both patients and clinicians. This study continues the postdoc work of Christopher Bennett, B.S.E.E. ’05, M.S.M.E.T. ’07, Ph.D. ’10, Frost School research assistant professor and jazz pianist. Bennett’s expertise in psychoacoustics makes him an invaluable collaborator on the Össur study because it requires deploying sounds to simultaneously convey a bevy of things—alert amputees when they’re doing something wrong, signal which movement is incorrect, and reward them when they improve their gait.

Össur engineers routinely visit the FORE Center from Reykjavik, Iceland to help implement and adjust all the sensors, accelerometers, gyroscopes, and other widgets in the study’s three microprocessor knee models—the Justin Bieber, the Lady Gaga, and the Britney Spears. The pop-star labels are Össur’s way of giving UM musician-researchers a chuckle as they keep track of each prototype.

The Britney Spears knee is actually the company’s Rheo Knee, worn by study participant Kelly Elizabeth, who, as an ER technician, a nursing student, and a mother, spends a lot of time on her feet. Elizabeth lost her leg in a boating accident in 2001 and was introduced to Gailey and the Össur study by her prosthetist Adam Finnieston. She travels from her home in Port St. Lucie, Florida, several times a week to the FORE Center, where wireless sensors on her body and floor sensors in the lab track her movements while she listens to her favorite songs on her iPod.

“At first I didn’t know what I was getting myself into,” she recalls. “But from the moment I put on [the Rheo Knee], I noticed a bounce in my step. It was—from what I remember—what it felt like to walk on two legs.”

One way the app can encourage good walking behaviors is through what Leider calls a “vocabulary of auditory penalty and auditory reward.” This can be done with pleasing or displeasing songs or sounds, or it can be done with auditory effects on your favorite music.

“If we want to convey that you did something good,” Leider says, “we might supply an enhanced bass response, or we might make it a little louder. We could also cue an auditory effect penalty, like bit crushing. You as a user don’t need to know anything about mixing. All you know is that the beautiful Norah Jones song you were just listening to now sounds like it came through a 1950s telephone.”

While music is one of the primary feedback systems in the app, it’s important to include other mechanisms. With eight different gait variations and multiple movements involved in those variations, a vast catalog of sensory signals is necessary to show users exactly what they’re doing wrong. 

Leider, Bennett, Gailey and Agrawal make the perfect team for the Össur study and other research opportunities that are bound to spring from it. Leider is quick to point out that the Frost School’s Music Engineering Technology program was the first music engineering program in the United States as well as “one of the few places in the country where you need to be a geek and you need to be passionate about music.”

“Nobody in medicine can do what the Music Engineering Technology folks can do,” Gailey says. “What we learn can be translated to Parkinson’s disease, people with balance issues, and so many other areas of study.”

Gailey, who has published dozens of research articles, returned wounded soldiers to active duty, and enabled double amputees to run like the wind on blades of steel, calls his work with Bennett and Leider “the most exciting project I’ve ever been involved with.

“I know this is the tip of the iceberg,” he continues, “and I can’t even see how far it’s going to expand.”

This is a shortened version of an article that first appeared in the Spring 2013 Score magazine published by the Frost School of Music. Click here to view an online version of the magazine.