6. The method of claim 1 , wherein the first and second portions are able to change in pitch and yaw at the third and fourth rod anchors, respectively, in response to movement of the spine during the correction.
1. A method of exerting a force on a spine, the method comprising: securing a first rod anchor on a first side of a spine to a first vertebra and securing a second rod anchor on the first side of the spine to a second vertebra; receiving a first portion of a first rod in the first rod anchor and a second portion of the first rod in the second rod anchor such that the first portion is substantially constrained against lateral translation and the second portion is substantially constrained against lateral translation, the first and second portions being able to change in pitch and yaw at the first and second rod anchors, respectively, in response to movement of the spine during a correction; locating a first stop feature along the first rod at a first position adjacent the first rod anchor and a second stop feature along the first rod at a second position adjacent the second rod anchor; imposing a first force on the first rod with the first and second stop features; and transferring the first force to the first side of the spine.