A surgical instrument includes a shaft assembly and an articulation control assembly. The shaft assembly includes an articulation section that is configured to deflect a distal end portion from the longitudinal axis. The articulation control assembly includes an articulation control member and a transmission assembly. The articulation control member is rotatably mounted relative to the shaft assembly. The transmission assembly is operatively connected between the articulation control member and the articulation section of the shaft assembly. The transmission assembly is configured to transmit selective manipulation of the articulation control member to the articulation section and selectively actuate the articulation section. The articulation control assembly is configured to lock without selective manipulation of the articulation control member to thereby inhibit actuation of the articulation section and unlock with selective manipulation of the articulation control member to thereby actuate the articulation section.