It could be called the “Goldilocks syndrome,” not too cold, not too hot, in the middle: just right. For people with weak knees, the same holds true according to a physical therapy MN study presented at the Radiological Society of North America meeting.
Researchers from the University of California in San Francisco revealed both high and low levels of exercise can damage knee in middle aged people. In the study, scientists used magnetic resonance imaging (MRI)-based T2 relaxation times to track the degeneration of the knee cartilage in adults over the years.
Trials included 205 patients between the ages of 45 to 60 who were asked to fill out a questionnaire regarding their lifestyle and levels of physical activity.
“T2 relaxation times generated from MR images allow for analysis of the biochemical and molecular composition of cartilage. There is increased water mobility in damaged cartilage, and increased water mobility results in increased T2 relaxation time,” said Wilson Lin, B.S., research fellow and medical student at UCSF.
According to estimates by Centers for Disease Control and Prevention, by 2030, about 67 million Americans over the age of 18 will have some form of diagnosed arthritis.
Results of the study showed that people who had higher levels of physical activity, especially the high impact ones like running, had more accelerated knee cartilage degeneration compared to other people. According to physical therapy in Minnesota experts, these people had a higher risk of developing 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. 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,” said Thomas M. Link, M.D., professor of radiology and chief of musculoskeletal imaging at UCSF.
Researchers found the use of T2 measurements in the study proved this method can be used to detect knee cartilage degeneration early, when the condition may still be reversible. The study concluded people who have high risk of osteoarthritis (people who have family history of the condition) need to maintain healthy weight and avoid high-impact activities.