Running often gets associated with adjectives like pounding, jarring and jolting, the rap for why running is bad for your joints. Because of the repetitive impact of running, yes, even trail running, runners often assume that long-term running will eventually lead to arthritis of the knees, hips or ankles. Many hang up their running shoes when confronted by arthritis’ warning signs, assuming its onset is imminent.
First the good news: runners are no more likely to suffer arthritis than non-runners, according to a 2010 review article in the Clinical Journal of Sports Medicine. Although the rate of injury among runners is high, osteoarthritis (OA) is by no measure the sport’s most common malady.
Arthritis, or more specifically osteoarthritis, is the degeneration of the articular cartilage that forms a cushion-like layer on the ends of the bones in each joint. Its loss leaves the bone susceptible to impact. The once-smooth cartilage becomes rough and cracked while the bone, without its protective layer, produces bone spurs. The pain often associated with arthritis arises not from the loss of cartilage itself but rather from trauma to the exposed, sensitive bone.
Impact or twisting forces, muscle weakness, joint instability and a history of previous joint injury can stress this important layer of cartilage and hasten the development of osteoarthritis. Given that with each stride the legs experience forces equal to several times a runner’s bodyweight, it’s no wonder runners fear the onset of injury.
“A fear that a running injury is arthritis is often the first question I hear from injured runners,” says Dr. Anthony Luke, director of the University of California, San Francisco’s Run Safe clinic, a running wellness program that focuses on injury prevention and biomechanical analyses.
Runners at Risk?
Indeed, theoretical arthritis research has generally supported the concept that repetitive stress leads to joint degeneration. Yet for runners, in an apparent contradiction, the scientific literature does not support any link between running and an increased risk of osteoarthritis.
“For 99 percent of individuals, running does not result in any increased risk of osteoarthritis,” says Dr. Stuart Willick, an osteoarthritis researcher at the University of Utah. Several possible explanations exist for this seemingly contradictory finding. One of the more compelling findings points to evidence that running seems to have a stimulating effect on the cartilage, suggesting that it may offer protection to healthy joints. Additionally, among people who do not exercise, obesity has been linked to increased risk of osteoarthritis.
A recent review of arthritis research in the journal Physical Medicine and Rehabilitation did not find a link between running and arthritis. In fact, one study examined rates of arthritis in former collegiate swimmers and runners between two and 55 years after graduation and found equal rates of hip and knee arthritis in the two groups.
In a study conducted by the Center for Disease Control, 5000 runners and walkers over the age of 20 were followed over a 13-year period. No association was found between running and either the incidence of arthritis or its progression. As with many other studies, the progression of arthritis was associated with greater body-mass index (BMI greater than 25), older age (over 50) and a history of prior knee injuries.
It’s not only the knees of runners that appear to resist the repetitive impact of running. A 2013 study by the Lawrence Berkeley Laboratory determined that, “Whereas other exercise increased OA and hip-replacement risk, running significantly reduced risk due, in part, to running’s association with lower BMI.”
As the bulk of research has concentrated on knee and hip osteoarthritis, limited information exists about the link between running and development of osteoarthritis at the ankles or lower back.
It is comforting that running does not seem to be associated with an increased risk of knee or hip arthritis. Perhaps most encouraging, older individuals, the population most commonly connected with arthritis, who run are less prone to OA than those who don’t. “The beneficial effects of running outweigh any potential risks, including osteoarthritis,” says Dr. Willick.
The Jury Is Out
A small number of studies have suggested a correlation between exercise, including running, and osteoarthritis. One of the studies had serious methodological flaws while another, a 2000 study in the Journal of Clinical Epidemiology, only found a positive association between osteoarthritis and increased levels of exercise in a limited subset of subjects.
Although the majority of research disputes the link between arthritis and running, the jury is still out on a link for those who run both long and/or fast. One such study examined the occurrence of hip arthritis in elite runners and found a greater incidence in those who ran over 65 miles a week. Although the researchers also found that faster running pace was even more a predictor of hip-joint cartilage degeneration, they did not indicate a specific pace for which risk increased.
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The act of running may not be the actual cause, arthritis can happen to runners. Says Dr. Luke, “Runners can develop osteoarthritis for a variety of reasons, including a history of previous injury or from a number of biomechanical and anatomic risk factors.”
The onset of arthritis is usually gradual, developing over a period of years. Typical symptoms include an increase in joint stiffness and popping and cracking that may or may not be associated with pain. In addition to pain during or after running, Dr. Luke’s red flag for runners is pain with daily activity.
Dr. Marc Safran of Stanford Sports Medicine advises runners with signs of osteoarthritis, “Osteoarthritis is progressive and irreversible and runners should make intelligent choices when it comes to modifying a running program to preserve the joints.”
Not content relying only on the traditional physical exam, Dr. Luke at the Run Safe clinic prefers using a treadmill to assess runners’ biomechanical form, watching for people who “run heavy” and can’t absorb the impact of running. Anatomic risk factors also include a knock-kneed or bow-legged gait.
Obtaining an accurate diagnosis from a sports-medicine physician is the first step when faced with the symptoms of knee, hip or ankle osteoarthritis. Conservative treatment is often the next step, and entails physical therapy focused on strengthening the leg muscles, particularly the quadriceps, glutes and hamstrings, which has proven helpful in both treating and preventing arthritis.
In a study published in the journal Medicine and Science in Sports and Exercise, researchers determined that those with higher levels of quad strength were less likely to suffer symptoms of knee arthritis, even when joint degeneration was present. Similarly, strengthening the gluteus medius and maximus muscles plays an important role in rehabilitating those with hip osteoarthritis.
Due to the many positive effects of exercise and running on blood pressure, bone density and body mass, many sports-medicine experts recommend modification of a running program rather than an outright stop. “Unless symptomatic, a diagnosis of osteoarthritis shouldn’t put a stop to a running program,” says Dr. Luke. “Instead, consider incorporating cross training, changing running surface and addressing possible biomechanical flaws.”
Modifying a running program can often allow those with mild to moderate osteoarthritis to continue running. The good news is that sports-medicine physicians like Dr. Luke feel that running on softer surfaces, like trails, lessens the impact of running and is easier on arthritic joints.
Signs and Symptoms of Osteoarthritis
- Pain during or after activity
- Tenderness around the joint (e.g. along one or both sides of the knee; hip/groin pain; front of ankle)
- Joint stiffness, particularly in the morning or after inactivity
- Loss of flexibility (e.g. hip OA may result in stiffness when attempting to bring the knee toward the chest; full bending or straightening of the knee may be limited, ankle stiffness may limit squatting or descending stairs)
- Popping, grinding or cracking
Tips for Running with Arthritis
- Reduce overall intensity and volume of running
- Cross-train with low-impact activities, e.g. cycling, swimming, Stairmaster, elliptical
- Strengthen the quads, hamstrings, glutes and calf muscles
- Maintain flexibility and joint mobility with a post-run general flexibility program
- Improve running form so the body can effectively dissipate and distribute impact
This story originally appeared in our October 2013 issue.