An ultrasonic surgical instrument comprises a shaft assembly including a waveguide, and an end effector arranged at a distal end of the shaft assembly and including an ultrasonic blade and a clamp arm. The instrument also comprises a base translatably coupled to shaft assembly. The base includes a first mechanical input and a second mechanical input. The instrument further comprises a closure actuation mechanism operatively connected between the first mechanical input and the clamp arm and configured to actuate the clamp arm from an open position toward a closed position upon selective drive of the first mechanical input. The instrument also includes an insertion actuation mechanism operatively connected between the second mechanical input and the shaft assembly and configured to actuate the shaft assembly from a proximal position toward a distal position upon selective drive of the second mechanical input for insertion of the end effector.