KALAMAZOO—People who are blind or have visual impairments could be the ultimate beneficiaries of a $421,125 grant awarded to Western Michigan University researchers to improve the design and use of canes.
The grant, from the U.S. Department of Health and Human Services, National Institutes of Health, was awarded to Drs. Dae Shik Kim and Robert Wall Emerson, associate professor and professor, respectively, of blindness and low vision studies, and Dr. Koorosh Naghshineh, professor of mechanical and aerospace engineering. The research team will study how to improve the ergonomic design and cane-use biomechanics to see what has the greatest impact on detecting obstacles and drop-offs in the walking environment.
Looking at cane materials, techniques for use
Kim, the project's principal investigator, says the long cane and how it is used was developed during the 1940s during World War II and has changed little since then, partly due to lack of research. Kim and his team hope to do something about that.
"Use of a long cane provides a preview of the environment, allowing blind people to detect drop-offs and obstacles on their walking paths," Kim says. "Failure to detect drop-offs or obstacles may result in falls and consequent fall-induced injuries. But the current long cane design and cane-use biomechanics do not seem to be adequate to provide reliable protection from such hazards."
Researchers will test whether cane rigidity, length, weight and weight distribution impact the ability to detect obstacles and drop-offs. Part of that will involve experimenting with different materials. Kim says aluminum was initially a popular material for cane shafts. Manufacturers then introduced graphite and fiberglass shafts.
"But no empirical research has shown the advantages and disadvantages of using different cane shaft materials," Kim says. "So one of the things we plan to do is systematically manipulate the rigidity, weight, weight distribution and length to see how those variables affect how well the person can detect drop-offs and obstacles."
How the cane is wielded is also a main focus of the three-year project, which began Feb. 1. The team will study employing the two-point touch technique, where the user lifts and taps the cane from side to side, bending at the wrist, and the constant contact technique, which keeps the cane tip in contact with the walking surface using a sweeping motion. Kim says the two-point touch technique may miss spots or shorter obstacles as the cane moves from side to side.
The study is actually a continuation of others Kim and his associates have conducted over the years. Kim decided to investigate canes and cane techniques after first noticing differences in the detection of obstacles and drop-offs with different cane techniques among his clients as an instructor at the Cleveland Sight Center. Since 2008, he has conducted a series of long cane studies with his colleagues at WMU.
In previous studies, Kim has experimented with different cane tips. Plain pencil-type tips can catch or snag in cracks and crevices, while "marshmallow" tips resembling the sweet snack, especially those equipped with a roller, can sweep more easily over a surface. Kim has found marshmallow roller tips are just as effective as marshmallow tips in detecting drop-offs.
Kim says the research has a wide application to the lives of those with visual impairments.
"Some blind individuals use a guide dog for their mobility," Kim says. "But that is a relatively small percentage of individuals. The vast majority use the long cane to get around. So by redesigning and improving its design, and also improving how the cane is used, we hope to improve the safety of blind individuals, which will obviously improve their quality of life."