By wearing a unique weighted back support device and participating in a special exercise program, women over 60 with osteoporosis-caused curvature of the spine improved their balance and experienced diminished back pain, giving researchers at Mayo Clinic a promising therapy to reduce falls among this population.
Falls present a serious risk of injury in the older population. Falls also can lead to permanent lifestyle changes, such as hospitalization, long-term rehabilitation and the inability to function independently, which can cause further declines in health.
Within four weeks in the study, the researchers noted significant changes in balance and gait. They also recorded back extensor strength improvements and significant decrease in back pain. Mayo Clinic researchers present their findings in the July 2005 issue of Mayo Clinic Proceedings.
"Most studies of falls address the effects of sedatives, weakness of the lower extremity muscles and neuromuscular diseases," says Mehrsheed Sinaki, M.D., of Mayo Clinic's Department of Physical Medicine and Rehabilitation. "What we wanted to see in this study was the effects of intervention to shift the center of gravity, and improve back strength and gait."
The Mayo Clinic researchers studied women in community-dwelling settings over age 60. Past studies have shown that community-dwelling people have a higher risk of falls and fractures than persons whose mobility is severely restricted. Twelve women in the study suffered from kyphosis, a progressive curvature of the spine that includes severe, progressive muscle weakness. Kyphosis causes a stooping posture. Their risk of falls and balance were studied and compared with a group of 13 women without this condition.
A fall is a biomechanical event, in that an external force -- gravity -- destabilizes the body's alignment of the torso over the legs. A fall occurs when the center of gravity of the person's trunk moves outside the base of support provided by the feet against the floor. The center of gravity is the imaginary point at which all the weight of the torso can be considered concentrated. If the base moves outside the base of support, a fall will occur.
At the start of the four-week comparison period, the two groups exhibited significant differences, but as the women with curvature of the spine continued the program, they showed improvements in balance, gait and back pain. The women used a weighted kypho-orthosis (WKO), a specially weighted back support device that centers its weight on the posterior of the spine and helps the person center her body better over her legs. It can weigh between 1.75 and 2.5 pounds, centered below the shoulder blades. A patient's doctor determines the best weighting and placement of the device.
Along with Dr. Sinaki, the principal investigator, Mayo Clinic researchers contributing to this study included Robert Brey, Ph.D., Christine Hughes, Dirk Larson and Kenton Kaufman, Ph.D.
In an editorial in the July Proceedings, Allan Tencer, Ph.D., of the Department of Orthopedics at Harborview Medical Center in Seattle, writes that the Mayo Clinic study "provides an excellent example of how an understanding of basic biomechanics can serve as a foundation for improving patient care."
Further research is now needed to determine the feasibility of using this intervention in large populations of patients with kyphosis, says Dr. Tencer.
"The report validates using the WKO and a dynamic exercise program to improve biomechanics in persons with kyphosis," says Dr. Tencer. "This, in turn, can reduce the possibility of the person falling and prevent the downstream, potentially life-altering consequences of falling."