A surgical device comprises a tube including a proximal segment and a distal segment and a plurality of force transmission elements coupled to the tube. The force transmission elements are actuatable to alter the distal segment of the tube between a flexible state and a stiffened state. The device also comprises a plurality of routing members. Each routing member is coupled to a wall of the tube. The routing members are configured to receive and route the force transmission elements along a length of the tube while permitting the length of the tube to flex and compress. The device also comprises a decoupling structure that generates a reduced force transmitted to the proximal segment when an applied force is applied to the distal segment by the force transmission elements.