A stabilization system for a human spine is provided. The stabilization system may include two dynamic interbody devices and/or one or more dynamic posterior stabilization systems. The dynamic interbody devices may be inserted into a disc space using a posterior approach. A first portion of a dynamic interbody device may contact a lower vertebra. A second portion of the dynamic interbody device may contact an upper vertebra. The first portion may be wider than the second portion to facilitate a large contact area against the lower vertebra and to facilitate insertion of the dynamic interbody device in the available space. The dynamic interbody devices may allow for coupled axial rotation and lateral bending of vertebrae adjacent to the dynamic interbody devices. The dynamic posterior stabilization systems may provide resistance to movement that mimics the resistance provided by a normal functional spinal unit.