Hard on the knees

ARTHRITIS sufferers are often advised to strengthen their quadriceps, the muscles at the front of the thigh, to ease knee pain and prevent arthritis from becoming worse. But for some people, such efforts may do more harm than good.  

As part of a Northwestern University study, more than 200 senior citizens had knee X-rays, measurements of quadricep strength, and knee alignment assessments. Eighteen months later, the procedures were repeated. The researchers reasoned that if having strong quads was protective, then those who began the study with stronger muscles would have less progression of arthritis.