Prevalence of Knee Osteoarthritis has Doubled

August 01, 2018

Since 1940, the rate of knee osteoarthritis among Americans has doubled. According to researchers this increase is not explained by longer lifespans or higher prevalence of obesity and overweight. The main culprit appears to be physical inactivity.


Researchers in this study looked at knee joints of 2,756 skeletons. They looked at the knees of those who lived in the 1800s through early 1900s, late 1900s through the early 2000s and those who lived between 6,000 and 300 BC. The first group was labeled “early industrial”, the second group “postindustrial” and the third group “prehistoric”.


The prevalence of knee osteoarthritis in the postindustrial group was 16%. The rate in the early industrial group was 6%. The prehistoric group came in at 8%. As noted earlier, after factoring in body mass index for the various groups, weight did not seem to be a contributing factor. The researchers felt that that the primary reason for the increased rate of osteoarthritis was inactivity.


The article points to the industrial revolution as a major factor in the decline in physical activity. As things became more mechanized, peoples’ jobs and lives became more sedentary. This increase in sedentary lifestyle seems to have led to an increase in the development of osteoarthritis.


The good news in this study, however, is that knee osteoarthritis is potentially a preventable condition. By increasing our physical activity, we may be able to reduce the likelihood of developing this disabling condition that often leads to joint replacement surgery.


Break out your Fitbits and start cranking out those steps. It may be your best defense against developing knee arthritis.


Study: Prevalence of Knee OA Today Twice What it Was 75 Years Ago; PT in Motion; Vol. 9, No. 10, November 2017.


Back to Blog