It may seem as if more people than ever are complaining about aching knees. In fact, such sentiment is not too far from the truth ‒ a large scale study has recently concluded that knee osteoarthritis has become far more widespread over the past several decades.
Going Back to the Past – the Ancient Past
This report appeared in August 29, 2017 issue of the Proceedings of the National Academy of Sciences, and was authored by researchers from a number of various academic institutions. A total of 2,756 skeletons were examined by this group, which were separated into three distinct categories:
- Skeletons from people who lived in the nineteenth century and early twentieth century. These were referred to as “early industrial” skeletons.
- Skeletons from subjects who were alive in the latter part of twentieth century and early 2000s. The study classified these samples as “”postindustrial” skeletons.
- Bones from prehistoric hunter-gatherers, who were estimated to have roamed the earth from 6,000 and 300 BC
Upon examining this diverse range of skeletal samples, the authors found osteoarthritis (OA) of the knees was far more common in post-industrial skeletons than in their pre-industrial counterparts. In the former group, the rate of OA was found to be at 16 percent, whereas this condition was present in just 6 percent of subjects from the 18th/early 19th century. For the prehistoric participants, this figure stood at 8 percent.
In order to confirm their findings, the authors also considered the Body Mass Index (BMI) and ages of the bones in the pre and postindustrial groups. Even with these factors added to the equation, the noticeable OA gap between the two sample sizes remained essentially intact.
A Lack of Action
Based on their findings, the research team contends that “independent risk factors” that are “either unique to or amplified in the postindustrial era” appear to be responsible for the rise in knee osteoarthritis. The researchers offered a fairly surprising explanation for this conclusion ‒ a persistent decrease in physical activity since 1940. In modern times, humans spending countless hours fiddling with smartphones, using laptops, watching TV and doing other sedentary activities, which might have the cumulative effect of weakening the knees’ cartilage and muscles.
Fortunately, the study does offer a possible solution to rising OA rates. The authors argue that an “effective prevention strategy” for this problem will probably “involve adjusting physical activity patterns and diets to approximate more closely the lifestyle conditions under which our species evolved.”