Osteoarthritis is a leading cause of disability in Canada. This type of arthritis causes deterioration in the joints, leading to swelling, pain and stiffness. It often results in lost work time and places limits on an individual’s normal function and recreational activity. Both the increasing prevalence of osteoarthritis in the province’s aging population, and the lengthy surgical wait times for replacing osteoarthritic joints are high profile health care issues in British Columbia. Physical activity can offer almost universal improvements in health, which includes decreasing the risk of heart disease, stroke, high blood pressure and cancer. Health Canada recommends all adults participate in at least 30 minutes of moderate-intensity exercise most days. But some types or too much physical activity, such as competitive sports or heavy physical work, can cause excessive wear and tear in the joints, increasing the risk of osteoarthritis. In addition, some people may be more vulnerable to the type or amount of physical activity because of the way their legs are aligned (e.g. bow-legged) and/or because of increased flexibility (hypermobility). Chuck Ratzlaff is comparing data on lifetime physical activity and these joint factors in people with knee and hip osteoarthritis to those who don’t have the condition, as part of a national arthritis study. The results can be used to recommend appropriate amounts and types of physical activities that may decrease the risk of osteoarthritis of the hip and knee.