Using a suitably constructed fiber optic cable and interrogation circuitry, the fiber optic cable can be positioned along an object to monitor its shape and the position of various points along the object thereon. Embodiments disclosed herein apply fiber optic position and shape sensing in various ways. In one embodiment, as subject's gait is monitored for analysis. In another embodiment, a tool is displayed moving within a patient's body. In an additional embodiment, the movement of a subject's head is tracked.
