An assembly including an adapter assembly (100) and an extension assembly (200) for connecting an end effector (30) to an electrosurgical instrument (10) is provided. The adapter assembly (100) includes a first pusher assembly (160) configured for converting rotational motion into linear motion. The first pusher assembly includes a pusher member (170) and first and second pawl assemblies (362, 364) for operable engagement with a flexible band assembly (230) of the extension assembly (200).
