Exercise for arthritis is underwhelming
Should exercise for knee and hip osteoarthritis be on my list of things that actually work for people in pain? I’m leaving it off because of a new study in The Lancet Rheumatology. Thanks for nothing, science!
This has been a crown jewel of evidence-based medicine. It’s in all the best clinical guidelines, as reliable as sunrise. Studies told us exercise helps, and in 2013 Uthman et al. wrote that “further trials are unlikely to overturn this result.” Verhagen et al. agreed in 2019: “adding new data is unlikely to change this conclusion.” A huge 2023 scientific review by Weng et al. that told us that it worked as well as common pain meds — not amazing, but definitely something.
Nice consensus you have there. Shame if something were to happen to it.
Fate loves a good dare, and this week’s featured paper says “hold my beer” and damns the benefit of exercise with the faintest of faint praise.
| title | Moderators of the effect of therapeutic exercise for knee and hip osteoarthritis: a systematic review and individual participant data meta-analysis |
|---|---|
| journal | The Lancet Rheumatology |
| Volume 5, Number 7, Jul 2023, e386––e400 | |
| authors | Melanie A Holden, Miriam Hattle, Jos Runhaar, Richard D Riley, Emma L Healey, Jonathan Quicke, Danielle A van der Windt, Krysia Dziedzic, Marienke van Middelkoop, Danielle Burke, Nadia Corp, Amardeep Legha, Sita Bierma-Zeinstra, Nadine E Foster, Jenny Brown, Carol Ingram, Sheila Hickson, Robert Taylor, Christine Walker, J Haxby Abbott, Kelli Allen, Kim Bennell, Daniel Bossen, Kanda Chaipinyo, Tom Cochrane, Mariëtte de Rooij, May Arna Risberg, G Kelley Fitzgerald, Helen French, Leigh Hale, Marius Henriksen, Rana S Hinman, Marijke Hopman-Rock, Michael Hurley, Justin Keogh, Cindy Veenhof, Jesper Knoop, Inga Krauss, Pazit Levinger, Christopher McCarthy, Stephen P Messier, Ari Heinonen, Havard Osteras, Shahnawaz Anwer, Ana Cristina R Lacerda, Shankar Ganesh, Benjamin Steinhilber, Yusuke Suzuki, Michael A Hunt, Laura Talbot, Carolien Teirlinck, Michael Doherty, Pao-Feng Tsai, Jason A Wallis, and Merve Yilmaz Menek |
| links | publisher • PubMed • PainSci bibliography |
Hard data mining
Holden et al. is a 2023 review of mostly the same data as past reviews, but fancier. This was an analysis of “individual patient data,” which is a more hardcore kind of meta-analysis. Instead of studying the pooled results of trials, they get the original data and started from scratch. It’s a lot of work, and Melanie Holden and fifty-three colleagues did the IPD thing for 4200 participants in 31 trials.
The results seem nice at first, highlighting a “positive overall effect of therapeutic exercise on pain and physical function in individuals with knee or hip osteoarthritis, compared with non-exercise controls.” Sounds familiar.
But it’s a small effect. Very small.
“This effect is of questionable clinical importance, particularly in the medium and long term.”
And that’s the news here. They concluded that exercise moved the needle just 6 points on a 100-point pain scale (on average). That’s much less than what people can even detect! And you cannot care about what you can’t feel.
And then it got worse beyond three months. 😬
We’ve always known exercise for arthritis delivered only a modest benefit, but there have been ominous signs that even that much may have been overestimated. For instance, a clever 2022 trial that found that it was no better than a placebo. And now this!
Any kind of regular exercise is good for arthritis… but only just barely.
Don’t ditch exercise (duh)
I’ve seen many pros dismiss this perspective: “Oh well, even if it doesn’t work well, it’s still a great idea for all kinds of reasons.” And that’s true! The other reasons …
- Although modest, the benefit is real — not a false positive, as so many allegedly positive studies are.
- The small-but-real benefit strongly emphasizes the lack of harm — that is, that “wear and tear” of exercise will not make you worse.
- The benefit is an average, so half of all people will do better, by definition. (And I bet it’s the ones in with greatest need, and who are the most out of shape to begin with.)
- Unlike most treatments, exercise has many other substantive benefits, such as “less dying.”
But let’s not deny the evidence in our eagerness to encourage exercise: the science is both good and bad news, and most people struggling with arthritis are not going to feel a difference, or just barely. Nuance strikes again.