In one embodiment, a method is disclosed for a robotic arm. The method includes pitching a linkage assembly having a plurality of links coupled in series together to constrain movement of a tool along an insertion axis; and enabling movement of the linkage assembly about a pitch axis with a strap drive-train coupled thereto using an electro-mechanical strap stack routed between a first link and a second link. The electro-mechanical strap stack includes a drive strap coupled to the linkage. The drive strap moves the linkage assembly.