A joint chain is any group of joints and their bones connected in a series. Joints are connected linearly, and their paths are drawn on screen by the bones. A joint chain begins at the highest joint in the chain’s hierarchy, and its bones are drawn pointing down the chain.
When you create a joint chain, the position of each joint should approximate the anatomical positions of the joints of the character you are trying to create. For example, if you are creating joint chains for the skeleton of a human biped model, you should place the joints at points of articulation such as the elbows, knees, ankles and so on.
