Abstract: This work deals with a 4-DOF flexible continuum robot that employs a spring as its backbone. The mechanism consists of two modules and each module has 2 DOF. The special features of the proposed mechanism are the flexibility and the backdrivability of the whole body by using a spring backbone. Thus, even in the case of collision with the human body, this device can ensure safety. In addition, the proposed mechanism has one kinematic redundancy in the configuration space and thus several motion planning algorithms can be exploited. The design and the kinematics for this continuum mechanism are introduced. The performance of this continuum mechanism was shown through experiment.