A medical instrument includes a medical-end-effector-associated member and resiliently flexible first, second and third elongate members. The medical-end-effector-associated member has a rigid portion positionable within a patient. The first, second and third elongate members each have a proximal end portion and a distal end portion. The distal end portions of the first, second and third elongate members are attached to the rigid portion of the medical-end-effector-associated member. Relative lengthwise translation of the proximal end portions of the first, second and third elongate members articulates the rigid portion of the medical-end-effector-associated member.