A new study presented at the Radiological Society of North America (RSNA) meeting in Chicago suggests that exercises like squats and lunges, which strengthen the quadriceps muscles in the thighs, may reduce the likelihood of needing total knee replacement surgery. This research, conducted by Dr. Upasana Upadhyay Bharadwaj, a research fellow in radiology at the University of California-San Francisco School of Medicine, sheds light on the protective role of strong thigh muscles against knee replacement.
The study is particularly relevant as about 14 million adults in the U.S. have knee arthritis, with over half likely to require knee replacement surgery. The quadriceps, located at the front of the thigh and known as the body’s strongest muscle group, are crucial for gait. The hamstrings, situated at the back of the thigh, are equally important for physical activity. These muscle groups counterbalance each other, allowing a range of activities while safeguarding the knee joint. An imbalance, along with other factors, can alter biomechanics and accelerate osteoarthritis progression.
The research team evaluated the thigh muscles of 134 participants from the Osteoarthritis Initiative, a nationwide study sponsored by the National Institutes of Health. They compared 67 patients who had a total knee replacement with 67 others who hadn’t undergone surgery, matching them for age and gender. AI analysis of knee MRIs revealed that a higher quadriceps-to-hamstring volume ratio significantly correlated with lower chances of knee replacement. Additionally, higher volumes of hamstrings and gracilis (a thin muscle inside the thigh) were linked to reduced knee replacement odds.
These findings indicate that strength training programs focusing on quadriceps relative to hamstrings could be beneficial. Bharadwaj noted that while overall muscle volume might be a marker for muscle strength, the balance between extensor and hamstring muscles could be more crucial and significantly associated with lower knee replacement odds.
The study’s implications extend beyond those at risk for osteoarthritis, suggesting that the general public could also benefit from incorporating appropriate strength exercises to preventively maintain knee health. However, since these findings were presented at a medical meeting, they should be considered preliminary until published in a peer-reviewed journal.
