You might not know, but there are almost 100 types of arthritis, but the most common cause of knee pain related to arthritis is osteoarthritis, a degenerative form of arthritis. It’s a condition marked by wear-and-tear of the joint. In fact, around one in three people over the age of 60 have evidence of knee arthritis on X-ray. In addition, the Centers for Disease Control and Prevention says that one out of 20 young and middle-aged adults have arthritis severe enough to interfere with their ability to work and function efficiently.
Is Exercise Good or Bad for Arthritis of the Knee?
The most common cause of knee pain related to arthritis is osteoarthritis, a degenerative form of arthritis. It’s a condition marked by wear-and-tear of the joint–and it’s common. In fact, around one in three people over the age of 60 have knee arthritis on x-ray.
What causes it? Because of aging, obesity, and sometimes injury or genetics, the cartilage in the knees wears away. Since cartilage acts as a buffer against stress and helps to cushion the joint against trauma, it’s not surprising that arthritic knees often become achy knees. However, research suggests that osteoarthritis may also have an inflammatory component.
The symptoms of knee osteoarthritis vary with the individual and the extent of the disease. In the early stages, some people experience no symptoms, but as the cartilage defects worsen, it’s common to experience knee pain and stiffness to varying degrees. Some people even experience joint swelling or weakness in the affected knee that comes and goes. The symptoms are often worse in the morning or after sitting for a long time. Also, prolonged or intense activity can worsen the pain and stiffness.
How Does Exercise Affect Knee Arthritis?
If sitting for a long period of time and inactivity worsens the symptoms of knee arthritis, movement would seem to be a way to ease knee soreness and stiffness. Does science support the idea that exercise helps the symptoms of osteoarthritis of the knee?
When you walk or do another form of exercise, it increases blood flow to the joint, and you get increased delivery of nutrients and oxygen to the synovial fluid, the fluid that bathes the joint. Exercise also builds strength and size in the thigh muscles, and this helps protect the knee joint.
But what does science say? A review of the literature published in Canadian Family Physician found that subjects who exercise don’t experience faster progression of their knee osteoarthritis. In fact, they enjoyed improvements in knee pain and had a lower risk of disability due to their knee problems. This is consistent with other literature that shows exercise doesn’t accelerate the progression of arthritis but may slow it down and improve functionality.
What about Running?
Even running, a high-impact exercise, doesn’t appear to worsen knee arthritis. In one study, researchers measured inflammatory markers in the synovial fluid of runners with knee osteoarthritis before and after a run. Levels of two important cytokines were lower after the run than before. These results suggest that running has an anti-inflammatory effect that may be beneficial for people with arthritis. Some pain people with arthritis experience is because of low-grade inflammation.
There’s also evidence that running doesn’t increase the risk of developing knee arthritis, contrary to what some sources say. Plus, exercise can lower body weight and that has a beneficial effect on knee arthritis by reducing the force that the knee has to bear. Exercise can actually thicken the cartilage in the knee. Most research looking at exercise and knee arthritis focused on moderate exercise and more may not be better. There is some evidence that exercise at a competitive level may increase the risk of osteoarthritis. However, a study of 75,000 runners published in 2013 found that running, even long-distance running, didn’t boost the odds of developing knee arthritis. In fact, runners in the study had a lower risk of developing arthritic knees.
Other lifestyle factors that increase the risk include obesity, injury to the knee, repetitive movements, anatomical problems, and obesity. Genetics are also a factor. You’re more likely to develop osteoarthritis if you have close family members with the disease. However, inheritance isn’t related to a single gene but multiple genes. So, you aren’t destined to get it even if you have family members with it.
Exercising with Arthritis of the Knee
Always consult with an orthopedic, sports medicine, or physical therapist professional before starting an exercise program. They will likely recommend low-impact exercise over high-impact exercise where both feet leave the ground. High-impact exercise places more stress on the knees and can worsen the soreness, although there isn’t strong evidence that it speeds up the progression of knee arthritis. You may also experience discomfort when you climb stairs. The key is to listen to your body and modify exercises that increase pain.
You also need resistance training to strengthen the muscles in the thigh that support and stabilize the joint. So, don’t neglect strength training. Stick to lighter weights and higher reps. You can still get strength and hypertrophy gains if you do enough repetitions to fatigue the muscles. Always do at least a 5-minute dynamic warm-up to increase the flexibility of the muscle. Let pain be your guide. If an exercise feels uncomfortable, modify it or don’t do it. It also helps to apply ice to your joints after a workout to prevent soreness and swelling.
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- “Inflammation May Affect Osteoarthritis”
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- Fernández-Moreno M, Rego I, Carreira-Garcia V, Blanco FJ. Genetics in osteoarthritis. Curr Genomics. 2008;9(8):542–547. doi:10.2174/138920208786847953.