RADIOLOGICAL SOCIETY OF NORTH AMERICA IMAGE: MR images of the right knee (A, B, C, D) at baseline (A, C) and after 48 months (B, D). Overweight 47-year-old woman in the elliptical trainer group (A-B) and overweight 64-year-old man in the racket sports group (C-D). The man in the racket sports group developed severe cartilage...
