Linda Frazier, a volunteer in Lockhart's Locomotion Research Laboratory, is outfitted with motion sensors and a wrist monitor system that can detect gait instabilities that might lead to falls. Lockhart and graduate student Jian Liu developed the wrist monitor for tests in the locomotion lab and in nursing homes. The ultimate goal is a comfortable monitor that can alert wearers and caretakers of potential falls.
The national importance of fall prevention
“If our research can save even one life, it will all be worthwhile,” said Thurmon Lockhart, an associate professor in the Grado Department of Industrial and Systems Engineering in Virginia Tech's College of Engineering, discussing his efforts to find ways to prevent falls among the elderly.
Capitol Hill agrees with Lockhart about the critical importance of this type of research. The U.S. Congress recently passed and President Bush signed Senate Bill 845, the Safety of Seniors Act of 2007, which directs the Secretary of Health and Human Services to expand research programs related to preventing elder falls.
“This legislation is timely,” Lockhart said. “Falls and resulting deaths have been increasing.” Falls are the leading cause of accidental deaths in the United States among people over the age of 75 and the second leading cause for those aged 45 to 75, according to the National Safety Council, and the number of fatalities due to falls increased steadily from 14,900 in the year 2000 to 17,700 in 2005.
Since coming to Virginia Tech and founding the Locomotion Research Laboratory, Lockhart - who is an affiliate faculty member of the Virginia Tech Center for Gerontology and the Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences - has devoted much of his time to learning how to prevent falls by investigating the relationship between aging and falling.
About five years ago in the lab, with funding from the Centers for Disease Control and Prevention and the National Institutes of Health, Lockhart and his student research assistants began suiting up young and old volunteers in a harness and a network of sensors that test musculoskeletal and neuromuscular changes and biomechanical responses during slips and recoveries.
As a test subject walks along an experimental platform in Lockhart's lab, the sensors monitor muscle and joint activities in the feet, ankles, legs, hips, and arms. At a random moment, a student quietly sprays a slippery substance on the platform behind the subject. On the way back, the subject slips and goes through the motions of recovery (an actual fall is prevented by the harness)
All the data from the monitoring sensors is fed into a computer model, providing information about the subject's gait while walking and the motions involved during slipping and recovery. Much of the success of the data collection is the result of the work of industrial and systems engineering Ph.D. student Jian Liu, from China, who for three years has been developing new and improved computer models for the lab.
Solving the mysteries of stability and mobility
A number of projects focused on elder falls have followed those earlier studies. Lockhart collaborated on an investigation of the “dynamic stability” differences between fall-prone and healthy adults with the late Kevin Granata, a professor of engineering science and mechanics and co-director of the Musculoskeletal Biomechanics Laboratory, who died on April 16, 2007.
“Our study showed that the fall-prone group demonstrated poorer dynamic stability - or stability while walking - than healthy elders and young adults,” Lockhart said. “One interesting finding was that stability was not influenced by walking speed.” Walking, as Lockhart pointed out, is actually controlled falling - and much depends on the stability of a walker's gait.
John Lach, an associate professor at The University of Virginia, is developing special accelerometers (sensors that detect changes in speed and direction of motion) for another of Lockhart's projects.
“Subjects wearing the accelerometers will be monitored in daily living simulations in the locomotion lab,” Lockhart explained. “They'll sit, stand, simulate kitchen chores, and other activities associated with all areas of the home.” The tests also will include induced falls on the harness platform.
In June 2007, Lockhart traveled to Sweden at the invitation of researchers at the University of Gothenburg to begin collaboration on an International Mobility Index. The Swedish research group, which includes Nobel Laureate Arvid Carlsson, has been collecting data on mobility since the 1970's.
The goal is to develop an index that can be accessed around the world and will enable health care providers to determine how likely people are to fall, as well as indicate specific problems such as brain atrophy, Lockhart said. His job, back at the locomotion lab, will be to devise a system with sensors and a computer network that can test and measure levels of mobility.
For more information on this topic, e-mail Lynn Nystrom, or call (540) 231-4371.