Despite previous beliefs, new research found that running does not cause osteoarthritis, but may actually prevent it.
Getting to know osteoarthritis
Osteoarthritis is a condition in which the cartilage that cushions joints breaks down over time. Without cartilage, the bones rub up against one another, causing pain, swelling and stiffness. Over time, people may have difficulty moving and getting through daily tasks. Approximately 27 million people have osteoarthritis in the U.S. Though there is no direct cause of the condition, certain ailments may pose as risk factors. Some of these include common sports injuries such as overuse of a joint, obesity, age, atrophied muscles and genetics. Osteoarthritis can affect any joint in the body, but will mainly affect the knees, hips and hands. The U.S. Centers for Disease Control and Prevention noted that 1 in 2 people over the age of 85 in the general public will develop knee osteoarthritis in their lifetime.
Previous findings on runners and knee osteoarthritis mainly examined elite male runners, which means the findings were not accurate for the general population. In the past, many people believed that running could damage knee joints by continually exerting pressure on them in the same motion. However, most runners are in good shape and have a lower body mass index, which helps protect against knee osteoarthritis.
The CDC recently released guidelines to the general public recommending that everyone participate in some sort of physical activity. The organization also noted that physical exercise is associated with a lower risk for poor cardiovascular health and mortality. Yet many people were concerned about the effects of physical activity on people with knee osteoarthritis. So, the Baylor College researchers decided to investigate.
“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,” lead study author Grace Hsiao-Wei Lo, M.D., said in a statement.
To determine if chronic running would negatively impact knee osteoarthritis, the researchers used data from a multi-center study known as the Osteoarthritis Initiative, which included 2,683 participants. Within this group, 56 percent were women, the average age was 64.5 and the average BMI was 28.6. Approximately 29 percent of the participants claimed they were runners at some point in their lives.
All of the patients were asked about symptoms, underwent knee X-rays and were asked to fill out a Lifetime Physical Activity Questionnaire that noted the top three most performed physical activities in their life. The activities were separated into various age ranges, including 12-18, 19-34, 35-49 and 50 years or older.
The researchers then followed up with all the participants 48 months later. The group underwent knee X-rays and then were rated on the chance of radiographic osteoarthritis. The American Family Physician noted that radiographic osteoarthritis is when signs of the condition are indicated through an X-ray. The participants were assessed using the Kellgren-Lawrence scale. Those with a 2 or higher were suspected to have radiographic osteoarthritis. Patients were also asked about their level of knee pain during the visit. The study authors believed that a patient had symptomatic osteoarthritis if he or she had one knee with considerable pain and radiographic osteoarthritis. Any person who had a total knee replacement was decided to have significant knee pain, symptomatic osteoarthritis and radiographic osteoarthritis.
After gathering the information, the researchers concluded that regardless of age, all runners were less likely to have knee pain, radiographic osteoarthritis and symptomatic osteoarthritis than people who did not run regularly. For those who used to run, 22.8 percent had symptomatic osteoarthritis compared to 29.8 percent of non-runners. Participants with the lowest BMI also ran the most. Even when it is not competitive, regular running can possibly lower the risk of developing knee osteoarthritis.
“This does not address the question of whether or not running is harmful to people who have pre-existing knee OA,” Lo said in a statement. “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 results reveal good news for runners and hopefully may encourage others in the general public to consider the hobby.