Strong Thighs May Mean Less Knee Pain for Women

Aug. 28 -- THURSDAY, Aug. 27 (HealthDay News) -- Stronger thigh muscles can help protect women, but not men, from the pain of arthritic knees, a new study finds.

The knee is the most common joint affected by osteoarthritis or degenerative joint disease, a major cause of disability in the United States, researchers say. In the United States, nearly 27 million adults suffer from osteoarthritis, and 16 percent of cases in people aged 45 and older affect the knee. Almost 19 percent of symptomatic knee osteoarthritis patients are women and 13.5 percent are men, according to the U.S. Centers for Disease Control and Prevention.

However, the new study finds that "stronger quadricep [thigh] muscles may protect older adults from developing the combination of osteoarthritis on X-ray and daily pain or stiffness in their knees," said lead researcher Dr. Neil Segal, director of the Clinical Osteoarthritis Research Program at the University of Iowa.

"We already knew that quadriceps strength was associated with better ability to walk and get up from a chair," Segal said. "However, one implication of these new findings is that quadricep strength may protect against developing symptomatic knee osteoarthritis."

The report is published in the September issue of Arthritis Care & Research.

For the study, Segal's team followed more than 3,000 men and women between 50 and 79 years of age, all of whom took part in the in the Multicenter Knee Osteoarthritis Study (MOST). The trial was designed to find out if knee strength would predict knee osteoarthritis, either as observed on an X-ray or through patient symptoms.

Over two and a half years, the researchers evaluated each participant for thigh muscle strength. Muscle strength between the quadriceps and the hamstrings was used to determine weakness in the lower leg muscles. To see if people developed osteoarthritis, the researchers took X-rays of the participants' knees at the beginning and end of the study. They also asked about pain, aching or stiffness in the knees.