A shaft assembly for a surgical instrument that includes a movable drive member. In at least one form, the surgical instrument includes a spine assembly that is couplable to the surgical instrument and has a surgical end effector coupled thereto by an articulation joint. The shaft assembly in one form includes a proximal firing member and an intermediate firing member that is coupled to a distal firing member. The distal firing member is configured for selective travel through the surgical end effector. At least one articulation driver is coupled to the surgical end effector to apply articulation motions thereto. A clutch assembly interfaces with the primary and intermediate firing members and the articulation driver such that when in an articulation orientation, movement of the drive member results in movement of the articulation driver and when in a firing orientation, movement of the drive member results in movement of the intermediate and distal firing members. A separate articulation motor may be employed to actuate the articulation driver.
