Hinge Joint

Upper Door Hinge

The door relating to the upper door hinge is like a bone. With the hinge joint or the door hinge it allows for bones or doors to move in 2 directions. With the hinge joint, it allows for free movement and side to side movement like the hinge on a door allows the door to move.

Allows motion in one and only one plane. Formed between 2 or more bones where bones can only can only extend or flex.