- Osteoarthritis, a condition that affects the joints, is growing increasingly common.
- Although exercise is a useful lifestyle intervention to ease pain, experts are unsure of the best type of exercise to prescribe.
- A recent analysis concludes that in patients with osteoarthritis of the knee, aerobic exercise is likely the most beneficial.
Although scientists have shown that exercise can alleviate the pain of osteoarthritis, previous studies investigating which type of exercise is most beneficial have been inconclusive.
A new systematic review and network meta-analysis compiles data from multiple studies to find a clearer answer.
Published in the
Osteoarthritis is a degenerative joint disease. Unlike rheumatoid arthritis, which is driven by an autoimmune reaction, osteoarthritis is caused by “wear and tear.”
Specifically, cartilage, which prevents bones from rubbing together at joints, is slowly degraded, causing pain and a loss of function. Most commonly, osteoarthritis affects the knee joint.
Osteoarthritis is becoming more prevalent. This increase is likely for a number of reasons, but two are particularly important. Firstly, it is increasing in line with the rise in obesity, which puts additional stress on joints. Secondly, because osteoarthritis is primarily associated with advanced age, the rising average age of the population also plays a part.
According to the authors of the new analysis, approximately 1 in 3 people over the age of 45 already have signs of osteoarthritis. More worryingly, half of these individuals already have severe knee symptoms.
Although there is a range of treatments, including medications, exercise should form an
The authors of the new paper write, “Many earlier studies failed to capture the full range of exercise types, leading to incomplete comparisons and reduced generalisability.”
Also, because osteoarthritis is a long term, progressive condition, they believe that not enough research has assessed the “short, medium, and long-term outcomes.”
Their new analysis helps bring some clarity to this important question.
As with any difficult-to-answer question, analyzing large amounts of good-quality data is a good way to develop a clearer picture.
In this case, the scientists combined data from 217 randomized controlled trials (RCTs), including a total of 15,684 participants.
All of the included studies focused on knee osteoarthritis only. Additionally, they all compared some form of exercise to either a control condition or another form of exercise. Studies also had to take into account at least one of these outcomes:
- function
- pain
- quality of life
- how well they could walk
- adverse events
Importantly, the authors also assessed each trial for its quality, including the risk of bias. Using this and other information, the researchers were able to evaluate the certainty of the evidence.
Once they had crunched many, many numbers, they concluded that, compared with control participants, aerobic exercises improved:
- Pain: Short-term and mid-term follow-up.
- Function: Short-term, mid-term, and long-term follow-up.
- Gait performance (Walking ability:) Short-term and mid-term follow-up.
- Quality of life: Short-term and mid-term follow-up.
However, other types of exercise also had benefits. Mind-body exercise, which combines cognitive focus and breathing exercises with physical activity, seemed to increase function.
Also, neuromotor exercises, which focus on aspects such as balance, coordination, walking, and agility, were particularly beneficial for walking ability in the short term.
Strength training and mixed exercise seemed to produce large increases in function at mid-term follow-up, and flexibility exercises resulted in significant pain reduction in the long term.
Importantly, none of the exercise types caused any more adverse events than was experienced by those in the control groups.
This study has limitations. Notably, it only applies to people with knee osteoarthritis — studies on people with knee and hip osteoarthritis, for instance, were removed from the analysis.
They also explain that many of the studies on this topic are not of high quality, and call for larger and higher-quality studies. Importantly, only 5.5% of the studies looked at longer-term outcomes, which is an important omission when attempting to understand a lifelong condition like osteoarthritis.
Medical News Today contacted Matthew Bennett, MD, an orthopedic spine surgeon and functional medicine expert who was not involved in the study.
When we asked about limitations, he said, “This was a well-designed and thoughtfully executed study. The researchers did an excellent job pulling together a massive amount of data and organizing it in a way that gives us a clearer picture than we’ve had before.”
“That said, no study is perfect,” he continued. “One of the biggest challenges here is that it groups very different activities into broad categories. Walking, cycling, and swimming are all considered ‘aerobic,’ but anyone with knee arthritis knows these don’t feel remotely the same.”
“Swimming is much lower impact. Cycling may be doable when walking isn’t. So while the category might show benefit overall, it doesn’t mean each individual activity is right for every person.”
— Matthew Bennett, MD
Although aerobic activity is already recommended, it is given a similar weight to other modalities.
Medical News Today reached out to Ashley Caravelli, MD, a board certified family medicine physician who was not involved in the research. We asked for her thoughts on the study:
“I think this study is great news for anyone with knee arthritis. It shows that simple aerobic exercise really helps to reduce pain and improve how people move and feel.”
“What surprised me most,” she continued, “was how much of a difference these activities made across so many people and types of exercise programs.”
In line with their findings, the authors recommend “aerobic exercise as a first-line intervention for knee osteoarthritis management, particularly when the aim is to improve functional capacity and reduce pain. While other exercises may offer complementary benefits to patients, they should not replace aerobic exercise as the primary strategy.”
Taken together, Caravelli told MNT that the study “suggests that regular movement is one of the most powerful tools we have.”
The authors of the new study recommend regular indulgence in aerobic activities, like cycling, walking, and swimming. However, they also explain that it is important to speak with your doctor before adopting new exercise routines.
“We often assume that if we have arthritis, our best days are behind us, or that we’re on a fixed path toward joint replacement. But that’s not always true,” concludes Bennett.
