fulcrum /fo͝ol″krəm, ful″-/ [L, fulcire, to support] , 1. the stable point or the position on which a lever, such as the ulna or the femur, turns. Numerous common body movements, such as raising the arm and walking, are combinations of lever actions involving fulcrums. The muscles provide the forces that move the numerous bones acting as levers. 2. (in radiology) an imaginary pivot point about which the x-ray tube and film move. During computed tomography the fulcrum lies in the focal, or object, plane, and only anatomical areas lying in this plane are focused and imaged.
