A device for modifying tissue in a spine may include: a shah having a proximal portion and a distal portion, the distal portion having dimensions which allow h to be passed into an epidural space of the spine and between target and non-target tissues at least one distal force application member extending from the distal portion of the shall and configured to facilitate application of at least one of anchoring force and tensioning force to the shaft; at least one movable tissue modifying member coupled with the shaft at or near its distal portion; at least one drive member coupled with the at least one tissue modifying member to activate the at least one tissue modifying member; and at least one power transmission member coupled with the at least one drive member to deliver power to the at least one drive member.