Running on a regular basis does not increase the risk of knee osteoarthritis (OA) after all, and could even help prevent it.
Osteoarthritis is the most common joint disease seen in middle-age and older individuals, and is characterized by a painful breakdown of joint cartilage, the American College of Rheumatology (ACR) reported. In the past researchers have suggested a link between running and the debilitating condition, but these studies have only focused on "elite male runners."
"Recent CDC guidelines recommend that all adults participate in regular physical activity, as there is definitive evidence that increased physical activity is associated with reduced cardiovascular events and mortality," said Grace Hsiao-Wei Lo, of Baylor College of Medicine and a lead author of the study. "However, the influence of these physical activities on knee OA is unclear. Since running is a common leisure physical activity that involves repetitive loading, which could be harmful to the joint, I was particularly interested in studying how habitual running relates to the development of knee OA."
To gain insight into the connection in the general population the researchers looked at 2,683 participants with a mean age of 64.5 and BMI of 28.6. Twenty-nine percent of the participants (who were 55 percent female) said they had ran regularly at some point in their lives. The patients were given an X-ray and symptom assessment and were asked to complete the Lifetime Physical Activity Questionnaire (LPAQ) that identified the top physical activities they had performed in their lives.
After 48 months the knee X-rays were scored for evidence of radiographic OA using the Kellgren-Lawrence (KL) grade scale; those with a grade of two or higher were considered to have radiographic OA (ROA). The patients were also monitored for frequent knee pain and were considered to have symptomatic OA (SOA) if they experienced this symptom in one or both knees or a total knee replacement.
The team found runners had lower instances of knee pain than those who had never ran despite what age they were when they participated in the activity.
"This does not address the question of whether or not running is harmful to people who have pre-existing knee OA," Dr. Lo said. "However, in people who do not have knee OA, there is no reason to restrict participation in habitual running at any time in life from the perspective that it does not appear to be harmful to the knee joint."
The findings were presented at the American College of Rheumatology Annual Meeting.
