What is an example location for an irregular joint?

An irregular joint is characterized by a structure that allows for limited movement and is not classified in the standard joint types like hinge or ball-and-socket. The carpals, which are the small bones in the wrist, exemplify an irregular joint because they have complex shapes that fit together in a way that allows for a variety of movements, such as gliding and limited rotation. This configuration does not fit neatly into the basic categories of joints, distinguishing them as "irregular."

In contrast, the elbow is a hinge joint that primarily allows for bending and straightening. The knee, while it has some degree of complicated movement, is also classified as a hinge joint, principally facilitating flexion and extension. The shoulder, although it possesses a ball-and-socket structure, is primarily known for allowing a wide range of motion in different directions but does not exhibit the irregularity seen in the carpals. Thus, the carpals are the clearest example of an irregular joint due to their unique shapes and functional characteristics.