Principles of Manual Medicine
Translation
When a rigid body translates along a straight line, we can say that there is one degree of freedom of motion. Driving your car across a bridge could be considered to be an example of translation along a single axis, assuming that you stay in your own lane. The term degree of freedom specifies the number of independent ways that a rigid body can move. Moving the mouse of your computer across the top of your desk is a example of an system that has two degrees of freedom of motion (the width and the depth of the desk forming two axes that define the position of the mouse). A body moving in translation can have no more than three degrees of freedom of motion. Vertebrae can have up to six degrees of freedom of motion. Vertebral bodies are able to translate along each of three orthogonal axes, and are also able to rotate about each of these same three axes.
Click here to see a vertebra translate along the X axis.
Click here to see a vertebra translate along the Y axis.
Click here to see a vertebra translate along the Z axis.