Women with Strong Thigh Muscles Protected from Knee Osteoarthritis
Posted Sep 05 2009 10:21pm
Researchers at the University of Iowa Hospitals and Clinics found that women with the strongest quadriceps muscles appeared to be protected against the development of knee osteoarthritis (OA).
The team, led by Neil Segal, M.D., M.S., followed over 3,000 women and men over a 2 ½ year period in the Multicenter Knee Osteoarthritis Study (MOST). The participants were between the ages of 50 and 79 years.
The goal of the study was to determine whether knee extensor strength would be a predictor of radiographic OA or symptomatic OA. Radiographic osteoarthritis is OA that can be determined through X-ray. Symptomatic osteoarthritis is OA that is determined by symptoms of pain, stiffness and aching on most days of the month.
Participants were evaluated for thigh muscle strength using a device that measures the strength of different muscle groups. X-rays were taken at the beginning of the study and at the end to determine whether there was evidence of OA. The participants were also surveyed at the beginning and end of the study to establish if frequent pain, aching or stiffness was present in the knee.
By the end of the study 5% men (48 of 680) and 10%women (93 of 937) developed OA detected by x-ray. In addition, at the conclusion of the study 10.1% of women and 7.8% of men displayed signs of symptomatic knee OA.
“Our results showed thigh muscle strength was not a significant predictor of radiographic knee OA,” concluded the authors.
Women in the top third of thigh muscle strength had a lower incidence of symptomatic knee OA, while men with strong thigh muscles had only slightly better odds of developing OA symptoms compared to men with weaker thigh muscles.
“These findings suggest that targeted interventions to reduce risk for symptomatic knee OA could be directed toward increasing knee extensor strength,” said Dr. Segal.
Details of this study appear in the September issue of Arthritis Care & Research.