title: Principles of ergonomic instrument handles.
abstract: Minimally invasive surgery (MIS) has become firmly established during the last decade. The advantages for patients are well recognised. Surgeons, however, must cope with disadvantages caused by an unergonomic working place. This includes architecture, operating room (OR) design, team interaction, equipment and, finally, posture and instrument handles. To prevent pressure areas, persisting nerve lesions, muscle cramps and fatigue caused by unergonomic tools it is necessary for the surgeon, both as a purchaser and user of laparoscopic instruments, to know the principles of ergonomically designed handles for MIS instruments. Anatomical, physiological and ergonomic facts are presented. An ideal ergonomic working posture for the laparoscopic surgeon and an optimal grasp for manipulating the instrument's functional elements are recommended. Criteria for genuine 'ergonomic handles' are established. These criteria enable the surgeon to evaluate ergonomic handles for MIS instruments according to his/her particular needs.