To the Editor: A 40-year-old recreational athlete recovering from a low back injury had acute scrotal swelling and pain several hours after performing stretching exercises for the lower back. There was no history of acute scrotal trauma during the previous week. The symptoms and swelling gradually subsided over a period of several days. Magnetic resonance imaging two weeks after the onset of symptoms demonstrated a subacute scrotal hematoma measuring 3 cm by 1 cm by 1 cm. Reenactment of the stretching routine demonstrated compression of the testes when one knee was brought to the chest and restrictive gym shorts were . . .