There are currently few Virtual Reality simulators for orthopedic trauma surgery. The current simulators provide only a basic recreation of the manual skills involved, focusing instead on the procedural and anatomical knowledge required. One factor limiting simulation of the manual skills is the complexity of adding realistic haptic feedback, particularly torques. This paper investigates the requirements, in terms of forces and workspace (linear and rotational), of a haptic interface to simulate placement of a lag screw in the femoral head, such as for fixation of a fracture in the neck of the femur. To measure these requirements, a study has been conducted involving 5 subjects with experience performing this particular procedure. The results gathered are being used to inform the design of a new haptic simulator for orthopedic trauma surgery.