Having stronger thigh muscles may lower the risk of total knee replacement surgery, according to a new study.
Researchers believe these findings could better inform strength-training programs for people with advanced arthritis in the knee.
In the US alone, 14 million adults have symptomatic knee osteoarthritis, and more than half of those are projected to eventually undergo total knee replacement surgery.
This study shows that stronger quadriceps muscles, relative to the hamstrings, may reduce the need for this surgery.
Dr. Upasana Upadhyay Bharadwaj of the University of California San Francisco said: “The two muscle groups act as counter forces, and the balance between them enables a wide range of activities while protecting the knee joint.
“An imbalance, in addition to other factors, leads to a change in the biomechanics resulting in the progression of osteoarthritis.”
The extensors, the muscles on the front of the thigh commonly referred to as the quadriceps, are the strongest muscle group in the body.
The muscles around the back of the thigh known as the hamstrings are responsible for extension of the hip and bending of the knee, making them equally essential for physical activity.
Dr. Bharadwaj continued: “Our study shows that in addition to strong muscles individually, larger extensor muscle groups—relative to hamstring muscle groups—are significantly associated with lower odds of total knee replacement surgery in two to four years.
“Although we presume that overall muscle volume is important as a surrogate marker for muscle strength, the ratio, hence the balance, between extensor and hamstring muscles may be more important and significantly associated with lower odds of total knee replacement.
“While these results are essential for targeted therapy in a population at risk for osteoarthritis, even the general public can benefit from our results to preventively incorporate appropriate strengthening exercises.”
To get their results the team studied thigh muscle volume in 134 participants.
They then compared the 67 patients who underwent total knee replacement with the 67 participants who had not undergone knee replacement.
They found that a higher ratio of quadriceps to hamstring volume was significantly associated with lower odds of total knee replacement.
The results also revealed that higher volumes of hamstrings and gracilis, a long, thin muscle on the inside of the thigh, were linked with lower odds of total knee replacement.
The full research will be presented today at the annual meeting of the Radiological Society of North America.
Produced in association with SWNS Talker
