Surgical Instrument

Provided herein is a tool for use in surgical procedures. The tool includes a portion having distal links and a portion having proximal links, each link being movable in multiple degrees of freedom relative to an adjacent link The tool includes an articulation mechanism for manipulating the distal links of the distal portion, the articulation mechanism including pairs of links and tension load bearing members. The tool includes an articulation lock between the distal portion and the proximal portion, each set of tension load bearing members connecting the proximal link and corresponding distal link of one of the pairs of links The articulation lock has a disengaged state wherein the links move freely and an engaged state wherein the adjacent distal links are forced into frictional engagement and the adjacent proximal links are forced into frictional engagement to impede movement of the distal and proximal portions.