: We examined 146 male professional soccer players before the 1999–2000 Belgian soccer competition. None of the
players had a history of muscle injury in the lower extremities in the previous 2 years. The flexibility of the hamstring, quadriceps,
adductor, and calf muscles of these players was measured goniometrically before the start of the season. All of the examined
players were monitored throughout the season to register subsequent injuries