The instrument comprises a body, a shaft assembly, an end effector, and an articulation joint. The end effector is operable to manipulate (eg, staple) the tissue. The articulating joint connects the end effector with the shaft assembly and allows the end effector to deflect in a direction away from the longitudinal axis of the shaft assembly. The articulating joint comprises a locking assembly operable to selectively lock the angular position of the end effector with respect to the longitudinal axis of the shaft assembly and an unlocking feature. The unlocking feature is operable to selectively unlock the locking assembly. The shaft assembly may further include a first movable member operable to selectively drive articulation of the end effector at the articulation joint position and a second movable member operable to selectively drive the unlocking feature 2 movable member. The second movable member is independently movable with respect to the first movable member.
