The surgical instrument includes a distal tool, a rigid or flexible elongated shaft that supports the distal tool, and a proximal handle or control member, where the tool and the handle are coupled to the respective distal and proximal ends of the elongated shaft via distal and proximal bendable motion members. Actuation means extends between said distal and proximal members whereby any deflection of said control handle with respect to said elongated instrument shaft causes a corresponding bending of said distal motion member for control of said working member. The proximal movable member comprises a movable ring assembly supported from the handle and adapted for three dimensional motion relative to the handle. A manually rotatable member may be arranged adjacent to the control handle for manually rotating the instrument shaft and working member relative to the control handle. A locking member may be supported from the control handle. The locking member is manually operable by a user and includes a follower the position of which is responsive to the position of the movable members.