A surgical instrument includes a shaft defining an axis, an end effector coupled to a distal portion thereof, a fixed handle coupled to a proximal portion thereof, a drive bar, a movable handle, and a linkage. The drive bar is disposed within the shaft and operably coupled to the end effector. The movable handle is movable relative to the fixed handle between open and closed positions and is coupled to the drive bar via a first pin on the axis. The linkage includes a first end portion coupled to the movable handle via a second pin and a second end portion coupled to the shaft via a third pin on the axis. In the closed position of the movable handle, the second pin is disposed in a near-over-center position relative to the axis to reduce a force necessary to maintain the movable handle in the closed position.