A flexure display is a display graph in which positions of a plurality of surface points and amounts of displacement are correlated. A slider provides a user interface for setting time. A time which is set through the slider is reflected on the flexure display or the like. The flexure display provides a graph showing an amount of displacement of each surface point at the time which is set through the slider. A load display shows a temporal change of an amount of load applied to the bone. A strain display shows a temporal change of an amount of strain of the bone. Time markers showing a predetermined time are displayed on the load display and strain display. The time markers are displayed according to the time which is set through the slider.