Too Much – Or Too Little – Activity Bad For Knees

Very high and very low levels of physical activity can accelerate the degeneration of knee cartilage in middle-aged adults according to a new study.

US researchers looked at changes in knee cartilage in a group of 205 patients aged 45 years to 60 years over a four-year period. Participants used a questionnaire to record their physical activity and the researchers used MRI technology to measure cartilage in the knee (T2 values).

The team found that frequently participating in high-impact activities (such as running) is associated with more degenerated cartilage and potentially a higher risk for development of osteoarthritis.

“When we compared the scores among groups, we found an accelerated progression of T2 relaxation times in those who were the most physically active,” says Prof Thomas Link who was involved in the study. “Those who had very low levels of activity also had accelerated progression of T2 values. This suggests that there may be an optimal level of physical activity to preserve the cartilage.”

Presented at the annual meeting of the Radiological Society of North America, the findings open up numerous areas for future inquiry, including analysis of the impact of specific types of physical activity on knee cartilage health.

“Lower impact sports, such as walking or swimming, are likely more beneficial than higher impact sports, such as running or tennis, in individuals at risk for osteoarthritis,” says Prof Link.