The AMA Guides are, as stated, practical guides for rating permanent impairment after an injury has reached Maximum medical improvement (MMI). Different states that use the Guides use terms like permanent impairment or partial permanent disability, to describe the extent of the injury. Each body part, be it bone, muscle, organ etc. are given a framework of motion or functionality that can be measured to establish how functional they are after an injury, in comparison to how functional the body part once was. In order to do this, doctors use a series of different tools and diagnostic tests to establish outcomes like range of motion, spinal asymmetry, mental health and more. These tests can range from the use of a paperclip to an MRI machine.