A dummy instrument for use in a simulator, the instrument comprising a control body (101) with user manipulatable angulation control (105), an insertion tube (102) and an umbilical (103) extending from the control body. In a real instrument corresponding to the one being simulated, at least one angulation cable would extend from the user manipulatable controls to the tip of the insertion tube such that movement of the angulation control changes the angulation of the tip. In the dummy medical instrument the angulation cable extends from the user manipulatable angulation control, and down the umbilical. The umbilical is releasably attached to a main unit (105). A motor (20,21) within the instrument at the distal end of the umbilical to applies a variable force to the cable. A position detector (30,31) within the instrument detects the angular position of the angulation control.