Regular running does not raise risk of knee arthritis
Regular running for leisure does not seem to increase the risk of later osteoarthritis (OA) of the knee, according to findings from a recent study.
If anything, runners may be at slightly lower risk of knee pain, US researchers say.
The study, part of the Osteoarthritis Initiative project, looked at frequent knee pain, radiographic OA (signs of osteoarthritis on X-rays etc) and symptomatic OA (symptoms reported by people) in a population sample of more than 2600 older Americans.
Prevalence of radiographic and symptomatic OA was actually lower in previous or current runners, although after adjusting for several variables, the researchers found no association between knee OA and running, rather than a decrease.
Those with a history of running were less likely to suffer frequent knee pain, and this was dose-dependent - i.e. the more they ran the less likely to suffer knee pain, the data showed.
However, the researchers caution that as this was an observational study, causality can’t be inferred and it’s possible people stopped running because they had knee pain.
They say the study supports the need for larger, longitudinal studies looking at non-professional running and knee OA.
They note that a high level of loading occurs in the knee during running and knee injury is common, which might intuitively lead people to suppose a high risk of knee OA.
They speculate that the lower BMI (body mass index) seen in runners might balance the loading effects of running.
“Since running is a strenuous exercise that requires related flexion and extension of the knee, it could improve proprioception (the body's innate spatial and movement perception) and periarticular muscle strength that may also reduce the risk of knee OA,” they write.
“Irrespective of the biologic pathway, the overall influence of running on knee OA when taking all the evidence into consideration does not appear to be harmful.”