A force transmission mechanism for a surgical instrument includes a worm drive, a lever arm, and an actuation element. The lever arm may include a follower member at a first end of the lever arm. The follower member engages the worm drive and is configured to be driven by the worm drive. The actuation element is connected the lever arm. The actuation element is configured to transmit force to actuate an end effector of the surgical instrument. Rotational movement of the worm drive imparts translational movement to the actuation element via the lever arm.