“Walking is so automatic,” says Assistant Professor Julie Stierwalt, “but we can get distracted from it. Think of cell phones.” The example resonates with anyone who has dodged a weaving, or suddenly stationary, cell talker on a sidewalk. Now consider distractions for a walker with Parkinson disease, already unsteady and vulnerable to falling.

That’s one research focus of Steirwalt and collaborators at the Neurolinguistic and Neurocognitive Rehabilitation Research Center, a joint enterprise of Tallahassee Memorial HealthCare, FSU College of Medicine, and Communication Disorders. Preventing falls has personal and national impact: “Broken bones for these elderly patients often mean long term care…sometimes never going home. And the healthcare cost exceeds $20 billion annually.”

To examine the effects of “talking” (linguistic/cognitive load) on walking (gait and balance), Stierwalt’s research design joined a simple task with ingenious technology. The Parkinson walkers and a control group undertook three graduated tasks: counting, subtracting by three’s, and continuing a patterned sequence like 5g, 6h, 7i (a cognitive load indeed). Speaking was video and audio recorded, and a rather magical “gait mat” recorded pressure, stride length and width, and toe- or heel-walking, with the gait pattern appearing on a computer screen.

Of interest was that all subjects took shorter, slower strides during the complex task. “When you’re doing two things and one gets harder,” Stierwalt says, “everyone compensates for the concentration. But a telling marker for the impaired walkers was ‘double support,’ when both feet are firmly planted.” The control group increased this stabilization, but those with Parkinson’s did not—or could not—leaving them more vulnerable to falls.

Stierwalt presented preliminary findings at the 2006 Inaugural World Congress on Parkinson Disease. The team is analyzing more data, including speech effects, but therapeutic applications appeared immediately. “In rehab centers,” she says, “ I often see therapists talking with patients while working on ambulation. Perhaps we shouldn’t give so much information, not ask questions or engage in conversations that requires a lot of thinking. Already Tallahassee Memorial is taking a close look at therapist’s behavior during gait training.” Multitasking, Stierwalt has shown, may be perilous, not productive.