People with knee osteoarthritis are encouraged to maintain an active lifestyle and to exercise those arthritic knees. But that seems counter intuitive — if your knees hurt, why would you move and exercise them more? This report based on over 2200 people with knee arthritis confirms (again!) the advice to exercise and stay active.
Where does this information come from? The study was done by the Osteoarthritis Initiative — a combination of publicly and privately supported researchers from around the United States. These investigators are from the well-known Rehab Institute of Chicago (RIC), Ohio State University, University of California (San Francisco), and Northwestern University School of Medicine.
Who was in the study? Men and women from age 45 up to 79 years were enrolled. They all had proven knee osteoarthritis (seen on X-rays) with joint narrowing and bone spurs. Some of the people had one knee involved (about one-third of the group), while others (60 per cent) had osteoarthritis in both knees.
Before starting the study, everyone was tested using a timed walk test and the chair-stand test. These are both tests that have been standardized and known to be good measures of physical function in people with arthritis. The walk test measures how quickly a person can walk 20 meters (25 yards). The chair stand test records how long it takes to get up and then sit back down from a chair five times.
Both of these tests require balance, coordination, flexibility, and strength. The knees are actively involved in both tests. The ability to walk, sit, and stand are practical ways to measure function needed to maintain independence in every day activities. The group also filled out a survey about lifestyle activity at home, routine sports or exercise, and walking outdoors.
Other before (baseline) measurements taken included height and weight (body-mass index or BMI), disease severity (calculated by the physician using X-rays), and symptoms (pain, stiffness, aching). A questionnaire assessing general health factors (e.g., smoking, depression, alcohol intake, other diseases or conditions present) was also completed by each person.
The patients weren’t given a specific exercise program to follow. They just went about their everyday ordinary activities. Then they were retested a year later with all the same test measures. When the data was analyzed, it was clear that people with higher activity levels had better knee function and less pain, stiffness, and aching.
One-fourth of the group actually increased their activity levels during the year’s time. Their performance improved on all the test measures. Patients who did the best were married and had a higher level of education. Participation in sports and exercise had the strongest link to best function. And it didn’t seem to matter what activities people were engaged in — participation in any and all were beneficial. Those who did the worst were older women (65 and older) and patients who were overweight.
The results of this study also agreed with others that have been done showing that severity of arthritis is not always linked with outcomes. People can have severe arthritis as seen on X-rays but good function and vice versa (minimal arthritis with the most severe symptoms).
The information obtained from this study was presented to the American College of Rheumatology at their annual scientific meeting in 2008. Getting the message out to physicians is an important part of helping patients with knee osteoarthritis. Other studies have shown that patients are more likely to respond with behavioral changes when physicians give them advice to stay active and when they prescribe exercise.
Older adults who are sedentary (inactive) can change their health status by increasing their activity level and engaging in regular exercise. This study supports the notion that exercising those arthritic knees will help improve symptoms and reduce disability.
The best advice physicians, public health professionals, and physical therapists can give older adults with knee osteoarthritis is to keep moving. Physical activity and exercise are proven to reverse decline and improve function.