A system for controlling movement of a remotely controlled steerable instrument comprises a flexible instrument. The flexible instrument comprises a steerable distal portion and a passive proximal portion. The steerable distal portion is configured to articulate to change a shape of the steerable distal portion. The system further comprises a shape sensing device comprising an optical fiber that spirals around the steerable distal portion. The optical fiber is configured to provide a signal indicative of the shape of the steerable distal portion. The system further comprises a controller in signal communication with the optical fiber. The controller is logically coupled to the flexible instrument and is configured to output a control signal to articulate the steerable distal portion of the flexible instrument in response to receiving at least the signal from the optical fiber.