Middle-aged men and women who engage in high levels of physical activity may be unknowingly causing damage to their knees and increasing their risk for osteoarthritis, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).
"Our data suggest that people with higher physical activity levels may be at greater risk for developing knee abnormalities and, thus, at higher risk for developing osteoarthritis," said Christoph Stehling, M.D., research fellow in the Department of Radiology and Biomedical Imaging at the University of California, San Francisco (UCSF) and radiology resident in the Department of Clinical Radiology, University of Muenster, Germany.
Osteoarthritis is a degenerative joint disease that causes pain, swelling and stiffness. According to the Centers for Disease Control and Prevention, osteoarthritis is the most common form of arthritis and affects an estimated 27 million American adults.
The UCSF study involved 236 asymptomatic participants who had not reported previous knee pain and were enrolled in the National Institutes of Health Osteoarthritis Initiative. Study participants included 136 women and 100 men, age 45 to 55, within a healthy weight range. The participants were separated into low-, middle-, and high-activity groups based on their responses to the Physical Activity Scale for the Elderly (PASE) questionnaire. PASE is a standard test that scores an older individual's physical activity level, based on the type of activity and the time spent doing it. Several factors contribute to the final PASE score, but a person whose activity level is classified as high typically might engage in several hours of walking, sports or other types of exercise per week, as well as yard work and other household chores.